CanIt-Domain-PRO Administration Guide

Transcription

CanIt-Domain-PRO Administration Guide
for Version 10.0.3
Roaring Penguin Software Inc.
9 September 2016
2
CanIt-Domain-PRO — Roaring Penguin Software Inc.
Contents
1
2
3
Introduction
19
1.1
Principles of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19
1.2
Handling False-Positives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
19
1.2.1
Spam-Control Delegation . . . . . . . . . . . . . . . . . . . . . . . . . . .
20
1.3
Organization of this Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
20
1.4
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21
Operation
27
2.1
Principles of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
27
2.2
Interaction between Whitelists and Blacklists . . . . . . . . . . . . . . . . . . . . .
28
2.2.1
RCPT TO: Actions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29
2.2.2
Post-DATA Actions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
30
2.3
Streaming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
2.4
How Addresses are Streamed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
33
2.5
How Streaming Methods are Chosen . . . . . . . . . . . . . . . . . . . . . . . . . .
34
2.6
Status of Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
36
2.6.1
Secondary MX Relays . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
37
2.7
The Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
37
2.8
Remailing Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
38
Realms
39
3.1
Introduction to Realms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
39
3.2
Realm Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
40
3.2.1
The base Realm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
40
3.3
Creating Realms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
40
3.4
Realm Mappings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
41
3.5
Determining the Realm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
42
3
4
CONTENTS
3.5.1
Mapping an Address to a Realm . . . . . . . . . . . . . . . . . . . . . . . .
42
3.5.2
Mapping a Login Name to a Realm . . . . . . . . . . . . . . . . . . . . . .
42
Realm Expiry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
43
3.6.1
Suspending Service to a Realm . . . . . . . . . . . . . . . . . . . . . . . . .
43
3.7
Realm Hierarchy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
43
3.8
Realm Custom Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
44
3.6
4
5
Streams
47
4.1
Introduction to Streams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
47
4.2
Realms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
47
4.3
The Definition of a Stream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
47
4.4
Users and E-Mail Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
47
4.5
Mapping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
50
4.6
The Home Stream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
50
4.7
The “default” Stream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
51
CanIt-Domain-PRO Setup
53
5.1
Accessing The Web Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
53
5.1.1
License Key Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
53
5.1.2
Login Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
54
5.2
The Setup Menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
55
5.3
Wizards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
56
5.3.1
Basic Setup Wizard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
56
5.3.2
RPTN Setup Wizard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
56
5.3.3
Dictionary Attack Detection Wizard . . . . . . . . . . . . . . . . . . . . . .
56
Verification Servers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
57
5.4.1
Wildcard Verification Server . . . . . . . . . . . . . . . . . . . . . . . . . .
59
5.4.2
SRS and Verification Servers . . . . . . . . . . . . . . . . . . . . . . . . . .
60
Mail Routing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
60
5.5.1
Outbound Relaying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
62
5.5.2
Outbound Relaying for Select Domains . . . . . . . . . . . . . . . . . . . .
62
Cluster Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
63
5.6.1
Bandwidth Optimization for Copying Files . . . . . . . . . . . . . . . . . .
64
5.6.2
Altering Services on a Cluster Member . . . . . . . . . . . . . . . . . . . .
64
5.6.3
Renaming of Cluster Members . . . . . . . . . . . . . . . . . . . . . . . . .
65
Known Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
65
5.4
5.5
5.6
5.7
CONTENTS
5
5.7.1
Associating Domains with Known Networks . . . . . . . . . . . . . . . . .
68
5.7.2
Overlapping Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
69
5.7.3
The SMTP-AUTH Pseudo-Network . . . . . . . . . . . . . . . . . . . . . .
69
Rate-Limiting Outbound Mail . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
69
5.8.1
Rate-Limiting by IP Address . . . . . . . . . . . . . . . . . . . . . . . . . .
71
5.8.2
Fine-Grained Rate-Limiting Rules . . . . . . . . . . . . . . . . . . . . . . .
71
5.8.3
Notes about Rate-Limiting Rules
. . . . . . . . . . . . . . . . . . . . . . .
73
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
74
5.9.1
Direct Queue Injection . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
74
5.10 System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
75
5.11 Templates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
76
5.12 Theme Customization and Branding . . . . . . . . . . . . . . . . . . . . . . . . . .
79
5.12.1 Creating or Editing a Customization . . . . . . . . . . . . . . . . . . . . . .
80
5.12.2 Emergency Recovery from Bad Theme Customization . . . . . . . . . . . .
81
5.13 HTTPS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
81
5.14 The Domain Mapping Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
81
5.15 The Address Mapping Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
83
5.15.1 Wild-Card Entries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
84
5.16 The default Stream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
85
5.17 Mapping Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
85
5.17.1 Central Scanning with Opt-Out . . . . . . . . . . . . . . . . . . . . . . . .
85
5.17.2 Single Domain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
86
5.17.3 Single Domain with Aliases and Mailing Lists . . . . . . . . . . . . . . . .
86
5.18 Pausing Delivery to Selected Domains . . . . . . . . . . . . . . . . . . . . . . . . .
86
5.18.1 Pausing Delivery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
86
5.18.2 Resuming Delivery . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
87
5.19 The Domain Overview Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
87
5.20 Autotask® Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
88
5.20.1 Preparing Autotask . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
88
5.20.2 Preparing CanIt-Domain-PRO . . . . . . . . . . . . . . . . . . . . . . . . .
90
5.20.3 Testing the Autotask Integration Settings . . . . . . . . . . . . . . . . . . .
93
5.20.4 Autotask Settings and Inheritance . . . . . . . . . . . . . . . . . . . . . . .
95
5.21 ConnectWise® Integration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
95
5.21.1 Preparing ConnectWise . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
95
5.21.2 Preparing CanIt-Domain-PRO . . . . . . . . . . . . . . . . . . . . . . . . .
103
5.8
5.9
6
6
CONTENTS
CanIt-Domain-PRO Administration
105
6.1
Global Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
105
6.2
SRS (Sender Rewriting Scheme) . . . . . . . . . . . . . . . . . . . . . . . . . . . .
109
6.3
Real-Time DNS Blacklists . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
110
6.3.1
Entering the Master List of DNS RBLs . . . . . . . . . . . . . . . . . . . .
110
6.3.2
combined.bl.rptn.ca . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
111
Phishing URLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
112
6.4.1
Malicious URL Votes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
112
6.4.2
Known Phishing URLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
114
6.4.3
Delaying Messages because of local Phishing Votes . . . . . . . . . . . . . .
115
Users . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
116
6.5.1
User Privileges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
117
6.5.2
Adding a User . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
117
6.5.3
Editing a User . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
118
6.5.4
Deleting a User . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
119
6.5.5
Granting Access to Streams . . . . . . . . . . . . . . . . . . . . . . . . . .
119
6.5.6
Switching Users . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
120
6.6
Permitting Users to Opt In . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
121
6.7
Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
122
6.7.1
Creating, Deleting and Editing Groups . . . . . . . . . . . . . . . . . . . . .
122
Viewing Active Streams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
123
6.8.1
Definition of an Active Stream . . . . . . . . . . . . . . . . . . . . . . . . .
124
6.8.2
The Active Stream Display . . . . . . . . . . . . . . . . . . . . . . . . . . .
124
6.8.3
Deleting a Stream . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
125
Filtering Outbound Mail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
125
6.9.1
. . . . . . . . . . . . . . . . . . . . . . . .
125
6.10 Copying Rules from One Stream to Another . . . . . . . . . . . . . . . . . . . . . .
128
6.11 Secondary MX Hosts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
129
6.12 Avoiding Backscatter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
130
6.13 Test Plugins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
130
6.13.1 The PhishingAddress Plugin . . . . . . . . . . . . . . . . . . . . . . . . . .
131
6.13.2 The PhishingURL Plugin . . . . . . . . . . . . . . . . . . . . . . . . . . . .
132
6.13.3 The OfficeMacros Plugin . . . . . . . . . . . . . . . . . . . . . . . . . . . .
132
6.13.4 The OfficeMacro* Open Plugins . . . . . . . . . . . . . . . . . . . . . . . .
132
6.14 Emergency Blocking of Delivery Status Notifications . . . . . . . . . . . . . . . . .
132
6.4
6.5
6.8
6.9
DKIM-Signing Outbound Mail
CONTENTS
7
6.15 Removing All Rules and Settings from a Stream . . . . . . . . . . . . . . . . . . . .
133
6.16 Provisioning Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
134
6.16.1 Computer-Readable Provisioning Information . . . . . . . . . . . . . . . . .
135
External Authentication
137
7.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
137
7.2
User Lookups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
137
7.2.1
IMAP and POP3 Authentication . . . . . . . . . . . . . . . . . . . . . . . .
139
7.2.2
LDAP Authentication and Streaming . . . . . . . . . . . . . . . . . . . . .
141
7.2.3
Program Authentication and Streaming . . . . . . . . . . . . . . . . . . . .
145
7.2.4
Program Authentication (Legacy Method) . . . . . . . . . . . . . . . . . . .
149
7.2.5
The account-info Script . . . . . . . . . . . . . . . . . . . . . . . . . .
149
7.2.6
The Rewrite User Lookup . . . . . . . . . . . . . . . . . . . . . . . . . . .
149
Authentication Mappings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
150
7.3
8
9
7
Bayesian Filtering
153
8.1
Introduction to Bayesian Filtering . . . . . . . . . . . . . . . . . . . . . . . . . . .
153
8.2
Unauthenticated Voting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
153
8.3
The Bayes Journal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
154
8.4
Site-Wide and Realm-Wide Bayes Training . . . . . . . . . . . . . . . . . . . . . .
154
8.5
RPTN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
154
8.6
Ruleset and Geolocation Data Updates . . . . . . . . . . . . . . . . . . . . . . . . .
155
Permissions
157
9.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
157
9.2
Stream Permissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
157
9.3
Determining Permissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
158
9.4
Granting Permissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
159
9.4.1
Granting Stream Permissions . . . . . . . . . . . . . . . . . . . . . . . . . .
159
9.4.2
Granting User Permissions . . . . . . . . . . . . . . . . . . . . . . . . . . .
161
Permission Grantability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
163
9.5.1
164
9.5
Grantability Algorithm . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
10 Streams, Inheritance and the Simple GUI
165
10.1 Simplification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
165
10.2 Stream Inheritance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
165
10.3 Special Streams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
167
8
CONTENTS
10.3.1 Final Streams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
167
10.3.2 Creating Special Streams . . . . . . . . . . . . . . . . . . . . . . . . . . . .
167
10.3.3 Deleting Special Streams . . . . . . . . . . . . . . . . . . . . . . . . . . . .
168
10.4 The Simplified GUI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
168
10.5 Inheritance from Non-Final Streams . . . . . . . . . . . . . . . . . . . . . . . . . .
169
10.6 Inheritance from Opted-Out Streams . . . . . . . . . . . . . . . . . . . . . . . . . .
169
11 Periodic Reports
171
11.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
171
11.1.1 Periodic Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
171
11.1.2 Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
171
11.2 Creating Charts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
173
11.3 Creating Periodic Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
173
11.4 Editing Periodic Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
174
11.5 Running a Report on Demand . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
175
12 Locked Addresses
177
12.1 Introduction to Locked Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . .
177
12.2 Preparing to use Locked Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . .
177
12.2.1 Create a new domain . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
177
12.2.2 Configure mail for the new domain . . . . . . . . . . . . . . . . . . . . . .
177
12.2.3 Inform CanIt-Domain-PRO about the locked address domain . . . . . . . . .
178
12.2.4 Associate each login name with an e-mail address . . . . . . . . . . . . . . .
178
13 Attachment Handling
179
13.1 General Filename and MIME Type Rules . . . . . . . . . . . . . . . . . . . . . . .
179
13.2 Delaying Attachments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
179
13.2.1 Enabling the Feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
179
13.2.2 Creating Delay Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
180
13.2.3 How It Works . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
180
13.3 Stripping Attachments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
181
13.3.1 Approving the Release of Stripped Attachments . . . . . . . . . . . . . . . .
182
14 URL Proxying
183
14.1 Configuring URL Proxying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
184
14.2 Proxying Known Phishing URLs . . . . . . . . . . . . . . . . . . . . . . . . . . . .
185
14.2.1 Known Phishing Test Point . . . . . . . . . . . . . . . . . . . . . . . . . . .
185
CONTENTS
9
15 SMTP Server Testing
187
15.1 An SMTP Primer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
187
15.2 Testing an SMTP Server . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
189
15.3 SMTP Test Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
190
16 CanIt Storage Manager
193
16.1 Storage Manager Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
193
16.1.1 Principles of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
194
16.2 Configuring the Storage Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . .
195
16.2.1 Enabling the Storage Manager . . . . . . . . . . . . . . . . . . . . . . . . .
195
16.2.2 The Configuration Wizard . . . . . . . . . . . . . . . . . . . . . . . . . . .
195
16.2.3 Local Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
197
16.2.4 Starting the Storage Manager . . . . . . . . . . . . . . . . . . . . . . . . . .
197
16.2.5 Data Stored in the Storage Manager . . . . . . . . . . . . . . . . . . . . . .
198
16.3 Backup Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
198
16.4 Running multiple Storage Managers . . . . . . . . . . . . . . . . . . . . . . . . . .
198
16.5 ps Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
199
17 Searching Logs
201
17.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
201
17.2 Log Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
201
17.3 Searching the Logs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
202
17.3.1 Performing a Search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
202
17.3.2 Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
203
17.3.3 Creating a Log Search Query . . . . . . . . . . . . . . . . . . . . . . . . . .
204
17.4 Saving Log Searches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
205
17.4.1 Managing Saved Log Searches . . . . . . . . . . . . . . . . . . . . . . . . .
205
17.5 Log Search Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
206
17.5.1 Detailed Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
206
17.5.2 Downloading Log Lines . . . . . . . . . . . . . . . . . . . . . . . . . . . .
207
17.6 Forwarding Logs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
208
17.6.1 Enabling Log-Forwarding . . . . . . . . . . . . . . . . . . . . . . . . . . .
208
17.6.2 Configuring Log-Forwarding . . . . . . . . . . . . . . . . . . . . . . . . . .
208
18 Tips
211
18.1 Greylisting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
211
10
CONTENTS
18.2 Don’t Trust Sender Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
212
18.3 Don’t Trust Sender Domains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
212
18.4 You May Trust Relay Hosts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
212
18.5 Custom Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
213
18.5.1 General Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . .
213
18.5.2 Things to avoid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
213
18.6 Group High-Scoring Messages Together . . . . . . . . . . . . . . . . . . . . . . . .
213
18.7 Roaring Penguin Best-Practices . . . . . . . . . . . . . . . . . . . . . . . . . . . .
214
18.8 General Anti-Spam Tips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
214
18.8.1 Use Receive-Only Addresses on your Web Site . . . . . . . . . . . . . . . .
214
18.8.2 Do Not Reply to Spam . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
214
19 Security
215
19.1 Don’t Run as Root . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
215
19.2 Ownership and Permissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
215
19.3 SSH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
216
19.4 PostgreSQL Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
216
19.5 PHP Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
216
19.6 Network Security . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
216
19.7 Backups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
217
A The Domain Configuration Wizard
219
A.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
219
A.2 Entering the Domain Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
219
A.3 Picking a Realm . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
219
A.4 Configuring Streaming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
220
A.5 Configuring Authentication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
221
A.6 Configuring Routing and Verification . . . . . . . . . . . . . . . . . . . . . . . . . .
222
A.7 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
223
B Release Notes
225
C A Testing Topology for CanIt-Domain-PRO
309
C.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
309
C.2 Assumptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
309
C.3 Network Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
309
C.4 Build the CanIt-Domain-PRO Server . . . . . . . . . . . . . . . . . . . . . . . . . .
310
CONTENTS
11
C.5 Configure the CanIt-Domain-PRO Server to Relay Mail . . . . . . . . . . . . . . . .
310
C.5.1
Enable Relaying . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
311
C.5.2
Configure Forwarding Relays . . . . . . . . . . . . . . . . . . . . . . . . .
311
C.5.3
Rebuild Sendmail Databases . . . . . . . . . . . . . . . . . . . . . . . . . .
311
C.6 Route Test Mail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
311
C.6.1
Direct Injection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
312
C.6.2
Create a Test Subdomain . . . . . . . . . . . . . . . . . . . . . . . . . . . .
312
C.7 Route Real Mail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
312
C.8 Outgoing Mail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
313
D CanIt-Domain-PRO Architecture
315
D.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
315
D.2 CanIt-Domain-PRO Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . .
316
D.3 Starting and Stopping CanIt-Domain-PRO . . . . . . . . . . . . . . . . . . . . . . .
317
D.4 Static Configuration Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
318
D.4.1 Database Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
318
D.4.2 Cron Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
318
D.4.3 MIMEDefang Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
319
D.4.4 Filter Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
321
D.4.5 Ticker Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
322
D.4.6 Storage Manager Settings . . . . . . . . . . . . . . . . . . . . . . . . . . .
322
D.4.7 Maintenance Notification . . . . . . . . . . . . . . . . . . . . . . . . . . . .
324
D.5 Tuning CanIt-Domain-PRO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
324
D.5.1 Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
324
D.5.2 Disk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
324
D.5.3 Solaris-Specific tmpfs Note . . . . . . . . . . . . . . . . . . . . . . . . . .
325
D.5.4 CPU . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
325
D.5.5 Sendmail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
325
D.6 Dealing with Overload . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
325
D.6.1 Tune CanIt-Domain-PRO and Sendmail . . . . . . . . . . . . . . . . . . . .
325
D.6.2 Network Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
326
E CanIt-Domain-PRO HOWTOS
327
E.1 Restoring a Database from a Dump . . . . . . . . . . . . . . . . . . . . . . . . . . .
327
E.2 Firewall Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
328
E.2.1
Firewall Rules: External Hosts . . . . . . . . . . . . . . . . . . . . . . . . .
328
12
CONTENTS
E.2.2
Firewall Rules: Internal Hosts . . . . . . . . . . . . . . . . . . . . . . . . .
328
E.2.3
Firewall Rules: Intra-Cluster Hosts . . . . . . . . . . . . . . . . . . . . . .
329
E.3 Running Something after the Nightly Cron Job Completes . . . . . . . . . . . . . .
329
E.4 Hooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
330
E.5 Migrating CanIt-Domain-PRO to a Different Machine . . . . . . . . . . . . . . . . .
330
E.5.1
CanIt-Domain-PRO Clusters . . . . . . . . . . . . . . . . . . . . . . . . . .
331
E.5.2
Storage Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
331
E.5.3
Migration Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
331
E.6 Cloning a CanIt-Domain-PRO Machine . . . . . . . . . . . . . . . . . . . . . . . .
334
F Using CanIt-Domain-PRO with memcached
F.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
335
F.2
Using memcached . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
335
F.2.1
Installing memcached . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
335
F.2.2
Configuring memcached . . . . . . . . . . . . . . . . . . . . . . . . . . . .
335
F.2.3
Single vs. Multiple Caches . . . . . . . . . . . . . . . . . . . . . . . . . . .
336
F.2.4
Configuring CanIt-Domain-PRO to use memcached . . . . . . . . . . . . . .
336
What is Cached . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
337
F.3
G Using CanIt-Domain-PRO with PgBouncer
339
G.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
339
G.2 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
339
G.3 Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
339
G.3.1 Configuring userlist.txt . . . . . . . . . . . . . . . . . . . . . . . . .
340
G.3.2 Configuring pgbouncer.ini . . . . . . . . . . . . . . . . . . . . . . . .
340
G.3.3 Configuring CanIt-Domain-PRO to use PgBouncer . . . . . . . . . . . . . .
340
H CanIt-Domain-PRO Logging
I
335
343
H.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
343
H.2 Event Log Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
344
SNMP Agents for CanIt-Domain-PRO
349
I.1
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
349
I.2
The SNMP Agent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
349
I.2.1
Enabling the agent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
350
I.2.2
Configuring SNMPd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
350
I.2.3
Agent Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
350
CONTENTS
J
13
Additional Scripts
353
J.1
353
reset-password.pl . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
K Bayes Database Back-Ends
355
K.1 PostgreSQL Bayes Data Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . .
355
K.2 Berkeley Database Bayes Storage . . . . . . . . . . . . . . . . . . . . . . . . . . .
355
K.3 CDB Database Bayes Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
355
K.4 Cluster Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
356
K.4.1 Propagating Updates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
356
K.5 Switching back to PostgreSQL Bayes Storage . . . . . . . . . . . . . . . . . . . . .
356
L System Check Tests
357
L.1 Disabling System Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
360
L.2 Anomaly Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
360
L.2.1
Disabling Recipient Verification Anomaly Testing . . . . . . . . . . . . . .
361
L.2.2
More Details about Anomalies . . . . . . . . . . . . . . . . . . . . . . . . .
362
L.2.3
Suppressing Anomaly Notification Emails . . . . . . . . . . . . . . . . . . .
362
M The CanIt-Domain-PRO License
M.1 THE CANIT DATA LICENSE . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Index
363
366
367
14
CONTENTS
List of Figures
2.1
Flow of Mail through CanIt-Domain-PRO . . . . . . . . . . . . . . . . . . . . . . .
28
2.2
RCPT TO: Decision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
29
2.3
Post-Data Decision . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
31
2.4
Address Streaming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
35
2.5
Database Agents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
37
3.1
Administrative Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
39
3.2
Realm Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
40
3.3
Realm Mappings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
41
3.4
Realm Hierarchy Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
44
3.5
Realm Custom Fields . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
45
4.1
Streaming Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
49
5.1
License Key Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
53
5.2
Login Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
54
5.3
Welcome Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
55
5.4
Verification Server Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
57
5.5
Verification Servers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
58
5.6
Domain Routing Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
60
5.7
Domain Routing Detail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
61
5.8
Cluster Management Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
63
5.9
Known Networks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
65
5.10 Known Network with Associated Domains . . . . . . . . . . . . . . . . . . . . . . .
68
5.11 Rate-Limiting Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
71
5.12 System Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
76
5.13 Templates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
77
5.14 Theme Customizations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
79
15
16
LIST OF FIGURES
5.15 Theme Customization Editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
80
5.16 Domain Mappings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
82
5.17 Address Mappings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
84
5.18 Domain Overview Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
87
5.19 Autotask Product List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
89
5.20 Autotask Recurring Service Contract . . . . . . . . . . . . . . . . . . . . . . . . . .
90
5.21 Autotask Integration Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
91
5.22 Autotask Test Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
94
5.23 Autotask Contract Costs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
95
5.24 CanIt-Inbound ConnectWise Product . . . . . . . . . . . . . . . . . . . . . . . . . .
96
5.25 CanIt Product List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
97
5.26 Integrator Login ID Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
98
5.27 CanItBilling Management IT Solution Setup . . . . . . . . . . . . . . . . . . . . . .
99
5.28 CanItBilling Managed Device Integration Setup . . . . . . . . . . . . . . . . . . . .
100
5.29 Connectwise Agreement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
101
5.30 Connectwise Agreement Addition . . . . . . . . . . . . . . . . . . . . . . . . . . .
102
5.31 ConnectWise Setup - Main Realm . . . . . . . . . . . . . . . . . . . . . . . . . . .
103
5.32 ConnectWise Test Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
104
6.1
Global Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
105
6.2
Master RBLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
110
6.3
Phishing URL Votes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
113
6.4
Known Phishing URLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
114
6.5
Users . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
116
6.6
Add User . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
118
6.7
Edit User . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
119
6.8
Granting Access to Streams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
120
6.9
Stream Opt-In Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
121
6.10 Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
122
6.11 Group Members . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
123
6.12 Active Streams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
124
6.13 Known Network with Associated Domains . . . . . . . . . . . . . . . . . . . . . . .
126
6.14 Adding a DKIM Key Pair . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
126
6.15 DKIM Key Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
127
6.16 Copying Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
129
LIST OF FIGURES
17
6.17 Test Plugins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
131
6.18 Block Delivery Status Notifications Page . . . . . . . . . . . . . . . . . . . . . . . .
133
6.19 Provisioning Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
134
7.1
User Lookup List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
138
7.2
User Lookup Wizard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
138
7.3
User Lookup: Method Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . .
138
7.4
IMAP/POP3 User Lookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
140
7.5
LDAP User Lookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
142
7.6
Program User Lookup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
145
7.7
Authentication Mappings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
150
9.1
Permissions Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
159
9.2
Permissions Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
159
9.3
Stream Permissions Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
160
9.4
User Permissions Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
162
9.5
Permission Grantability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
163
9.6
Grantable Permissions Detail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
164
10.1 Stream Inheritance Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . .
166
10.2 Stream Inheritance Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
166
10.3 Special Stream Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
167
10.4 Simplified Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
168
11.1 Periodic Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
173
11.2 Add Periodic Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
174
13.1 Delayed Attachments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
180
13.2 Attachment-Stripping Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
181
14.1 Redirected Link . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
183
14.2 URL Proxy Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
184
15.1 SMTP Session . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
188
15.2 SMTP Server Test Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
189
15.3 SMTP Server Test Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
190
16.1 CanIt Storage Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
194
18
LIST OF FIGURES
16.2 Storage Manager Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
196
17.1 Log Search Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
202
17.2 Saved Log Searches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
205
17.3 Log Search Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
206
17.4 Log Search Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
207
17.5 Log Forwarding Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
208
A.1 Domain Configuration: Enter Domain Name . . . . . . . . . . . . . . . . . . . . . .
219
A.2 Domain Configuration: Enter Realm Name . . . . . . . . . . . . . . . . . . . . . .
220
A.3 Domain Configuration: Configuring Streaming . . . . . . . . . . . . . . . . . . . .
220
A.4 Domain Configuration: Configuring Authentication . . . . . . . . . . . . . . . . . .
221
A.5 Domain Configuration: Configuring Routing and Verification . . . . . . . . . . . . .
222
C.1 Network Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
310
D.1 CanIt-Domain-PRO Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . .
316
L.1 Anomaly Notice . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
360
L.2 Anomaly Details . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
362
Chapter 1
Introduction
CanIt-Domain-PRO is server-based anti-spam software that stops spam from entering your network.
This guide explains how to administer CanIt-Domain-PRO, and is intended for e-mail administrators.
For installation instructions, please see the Installation Guide, and for end-user instructions, see the
User’s Guide.
1.1
Principles of Operation
CanIt-Domain-PRO uses many sophisticated rules and mechanisms to detect spam. These rules include those in an open-source anti-spam package, and are very effective and broad-spectrum. Once
CanIt-Domain-PRO decides that a message is probably spam, it is held for review.
You can configure CanIt-Domain-PRO to return an SMTP “temporary failure” code to the sending
relay host for any message held for review. In this way, the message body is held in the sender’s spool
directory and not in yours. A more complete description of how CanIt-Domain-PRO operates is given
in Chapter 2.
1.2
Handling False-Positives
Although CanIt-Domain-PRO’s rules for identifying spam are very accurate, no purely automated process can be 100% correct. That is why CanIt-Domain-PRO relies, in the end, on human intervention.
In this way, it can guarantee that no legitimate e-mail message will ever be rejected, and you will never
lose an important e-mail because of automated scanning.
At first glance, it seems that requiring human intervention is a step backwards—spam messages again
must be reviewed by a person. In reality, CanIt-Domain-PRO still saves time and money for the
following reasons:
• CanIt-Domain-PRO includes many features to lower your workload. (These features are described later in this manual.) You can scan and categorize e-mail messages using CanIt-DomainPRO much more quickly than using mail reader software.
19
20
CHAPTER 1. INTRODUCTION
• As time passes, you will begin recognize mailing-list traffic and other traffic that tends to be
falsely flagged as spam, and tell CanIt-Domain-PRO to always whitelist that traffic. Over time,
this reduces the amount of human intervention required.
• If you are willing to take the risk of inappropriately rejected messages, you can configure CanItDomain-PRO to automatically reject very high-scoring messages.
1.2.1
Spam-Control Delegation
CanIt-Domain-PRO operates similarly to CanIt-PRO, except that it allows two levels of administrative
delegation. In CanIt-PRO, the system administrator can create separate streams. Stream owners can
review quarantined mail within their streams. Only the single system administrator can create streams.
In CanIt-Domain-PRO, however, the system administrator creates realms, each of which has its own
Realm Administrator. Realm Administrators, in turn, can create streams, each of which has a Stream
Owner responsible for settings within the stream.
Settings in different streams do not affect other streams.
1.3
Organization of this Manual
This manual is divided as follows:
Chapter 1, “Introduction”, is this chapter. You should familiarize yourself with the terms in Section 1.4
before proceeding.
Chapter 2, “Operation”, describes the principles behind CanIt-Domain-PRO’s operation.
Chapter 3, “Realms”, describes Realms. A Realm is a complete administrative unit in CanIt-DomainPRO. You must read and understand this chapter before using CanIt-Domain-PRO in production.
Chapter 4, “Streams”, describes the concepts behind streaming. You must read and understand this
chapter before using CanIt-Domain-PRO in production.
Chapter 5, “CanIt-Domain-PRO Setup”, describes basic setup steps you need to take to configure
CanIt-Domain-PRO.
Chapter 6, “CanIt-Domain-PRO Administration”, describes tasks undertaken by the CanIt-DomainPRO administrator.
Chapter 7, “External Authentication”, describes how to integrate CanIt-Domain-PRO with an external
authentication mechanism (such as LDAP or POP3.)
Chapter 8, “Bayesian Filtering”, explains CanIt-Domain-PRO’s Bayesian filtering module. Bayesian
filtering uses statistical analysis and training so that CanIt-Domain-PRO “learns” to recognize spam
based on user feedback.
Chapter 9, “Permissions”, describes how to control access to various parts of the CanIt-Domain-PRO
Web interface.
Chapter 10, “Streams, Inheritance and the Simple GUI”, describes how the CanIt-Domain-PRO administrator can set up different groups of spam-handling settings and allow end-users to select from
1.4. DEFINITIONS
21
one of a limited number of predetermined setups. The simplified interface is very useful if you wish
to provide “canned” settings for unsophisticated users.
Chapter 12, “Locked Addresses”, describes how CanIt-Domain-PRO permits users to generate addresses that they can give out to strangers, but that those strangers cannot in turn give or sell to
third-parties.
Chapter 13, “Attachment Handling”, describes CanIt-Domain-PRO options for handling various attachments.
Chapter 14, “URL Proxying”, describes a CanIt-Domain-PRO feature that can help mitigate phishing
attacks that trick users into visiting hostile web sites and entering sensitive information.
Chapter 15, “SMTP Server Testing”, describes a CanIt-Domain-PRO feature that lets you run a debugging SMTP session against a back-end mail server.
Chapter 17, “Searching Logs”, describes CanIt-Domain-PRO’s log-indexing and searching feature
(available only on appliance builds.)
Chapter 18, “Tips”, contains guidelines for reducing the workload of the spam-control officer and
dealing with spam more effectively.
Chapter 19, “Security”, contains information about CanIt-Domain-PRO security.
Appendix C, “A Testing Topology for CanIt-Domain-PRO”, gives tips on how to test CanIt-DomainPRO before putting it into production. This appendix also contains useful information on production
network topology, so if you are planning on using CanIt-Domain-PRO as a relay-only server, you
should read this appendix.
Appendix D, “CanIt-Domain-PRO Architecture”, discusses CanIt-Domain-PRO’s filter architecture
in detail. It provides tips on tuning CanIt-Domain-PRO and describes the various configuration files
used by CanIt-Domain-PRO.
Appendix E, “CanIt-Domain-PRO HOWTOs”, gives short “how-to” recipes for performing common
CanIt-Domain-PRO administrative tasks, such as restoring a database from the text dump, or moving
CanIt-Domain-PRO to another machine.
Appendix H, “CanIt-Domain-PRO Logging”, explains how CanIt-Domain-PRO logs statistics, warning, and error messages.
Appendix J, “Additional Scripts”, describes some additional scripts bundled with CanIt-Domain-PRO
that you might find useful.
1.4
Definitions
We use many terms related to Internet e-mail in this manual. Here is a definition of some of the terms
we use.
API Application Programming Interface. In the context of CanIt-Domain-PRO, the API is a method
for interacting with CanIt-Domain-PRO from a program or script.
Backscatter Unwanted DSNs (see “DSN”) caused when e-mail systems respond to faked sender
addresses.
22
Bayesian Analysis is a method whereby an anti-spam system keeps track of how often words appear
in spam and non-spam. Once enough statistics have been accumulated, the system can calculate
the likelihood that a new message is spam.
Blacklist A list of domains, senders or hosts that are blocked from sending e-mail.
CIDR “Classless Inter-Domain Routing”. A method for specifying an entire set of contiguous IP
addresses.
CanIt-Domain-PRO is an enhanced version of CanIt-PRO that allows two levels of delegation of
responsibility. See the next three definitions for more details.
CanIt-PRO is an enhanced version of CanIt that allows flexible delegation of spam-control responsibilities rather than requiring a single spam-control officer.
CanIt is extra software built on top of MIMEDefang that provides sophisticated spam-management
functions.
Cron A UNIX program that runs tasks periodically.
DKIM “DomainKeys Identified Mail”. A mechanism for proving that a particular organization’s
servers have relayed an email message. DKIM uses cryptographic techniques to assert that a
particular domain name is responsible for relaying the message. For more information, see
http://www.dkim.org/.
DMARC “Domain-based Message Authentication, Reporting and Conformance”. A mechanism for
allowing domain owners to specify a policy that recipients should use in response to potentiallyspoofed messages from that domain. For more information, see https://dmarc.org/.
DNS “Domain Name System”. The mechanism used on the Internet to translate host names to IP
addresses and more generally, to associate various sorts of information with domain names.
DSN “Delivery Status Notification”. A message generated automatically to notify senders of problems or failure to deliver an e-mail.
Daemon A long-running UNIX program that typically starts at system boot and continues running in
the background until the system is shut down.
Envelope Mail messages often have headers specifying the sender (the “From:” header) and recipients (typically the “To:” header.) However, SMTP has a completely separate set of commands
for specifying the sender and recipients. The sender and recipients specified in the SMTP commands are referred to as the envelope sender and envelope recipients, and do not necessarily
match the information in the message headers. CanIt-Domain-PRO uses both the Header From
and Envelope Sender address in Sender and Domain rules. It always uses only Envelope Recipients in its recipient rules.
Envelope Sender The sender address used in the “MAIL FROM” SMTP command. This is not
necessarily the same as the Header From address. Most email readers display the Header From
address rather than the Envelope Sender address.
1.4. DEFINITIONS
23
Hash An algorithm that computes a short “signature” given a chunk of data. Different inputs are
very likely to yield different signatures, so that a signature can be considered as a short-hand
identifier for the original data.
Header From The sender address used in the “From:” header of an email message. This is the sender
address displayed by most mail readers. See Envelope Sender for information about the SMTP
sender address.
Greylisting A technique to block spam from certain spam-sending software. It works by issuing a
Temporary Failure Code the first time an e-mail arrives from an unknown sender and IP address.
Legitimate SMTP servers will retry, allowing the message to be delivered. Some spam-sending
software does not retry, and messages sent by such software will be blocked without any contentscanning if greylisting is enabled.
Joe-Job A technique in which spammers fake the sending address to be that of an innocent victim,
who often receives DSNs (see “DSN”) and complaints.
Malware is software designed with a malicious purpose in mind. Examples of malware are viruses,
trojans, and keyloggers.
MIMEDefang is a free (GPL’d) e-mail scanning program that integrates with Sendmail’s Milter API.
It forms the basis for CanIt.
MIME “Multipurpose Internet Mail Extensions”. A set of rules for encoding different types of attachments as plain-text messages for transmission over SMTP.
Milter is a Sendmail interface that allows external programs to listen in on the SMTP dialog, and
potentially modify Sendmail’s actions and SMTP responses.
Permanent Failure Code Also called reject, this is a code sent to a relay host telling it that e-mail
transmission has failed and will not succeed. (For example, this code is sent if someone tries to
send e-mail to a nonexistent user.) The relay host typically e-mails a failure notification to the
original sender and discards the message.
Phishing An attack in which someone forges e-mail pretending to be from a security organization,
a bank, etc. and convinces naive users to reveal sensitive information like user-names and
passwords.
PostgreSQL A free and open-source SQL database heavily used by CanIt-Domain-PRO.
Ransomware is a specific type of malware. It typically makes changes on your computer that are
almost impossible to undo (such as encrypting all your files) and then demands payment within
a short period of time to undo the damage.
Ratware is software dedicated to sending out large volumes of spam.
RBL “Real-time Blocklist”. A DNS-based system for checking in real-time whether or not hosts or
domains should be blocked.
RPTN is the Roaring Penguin Traning Network. This is a system whereby multiple CanIt-DomainPRO installations can share Bayes training data.
24
RSS stands for “Really Simple Syndication” and is a format for publishing “news feeds” on the Web.
CanIt-Domain-PRO can produce an RSS feed showing pending incidents.
Realm Administrator is a user with administrative privileges in a realm. Unlike the System Administrator, a Realm Administrator can only administer his or her own realm.
Realm is a “virtual CanIt-PRO”. Within a realm, realm administrators can create streams for endusers, and streams in one realm are independent of streams in another realm.
Relay Host When a mail server wishes to transmit e-mail to your server using SMTP, it establishes
a connection with your mail server. The machine attempting to transmit mail to your server is
called a relay host.
REST Representational State Transfer. An architectural style for interacting with an API over HTTP
or HTTPS. CanIt-Domain-PRO’s API is REST-based.
Root Privileges A CanIt-Domain-PRO user with root privileges can create other users and configure
basic operating parameters. Also, he or she can edit other users’ preferences and stream settings.
SMTP Dialog During the course of e-mail transmission, the two ends of an SMTP connection transmit commands and results back and forth. This conversation is called the SMTP dialog.
SMTP “Simple Mail Transfer Protocol”, as described in Internet RFC 2821. This is the protocol used
to transmit e-mail over the Internet.
SPF stands for “Sender Policy Framework”. It is a mechanism that allows a domain’s administrator
to list which hosts are allowed to originate e-mail claiming to come from that domain. For more
details, please see http://www.openspf.org.
SRS stands for “Sender Rewriting Scheme”. It is used in conjunction with SPF to avoid spurious SPF
failures when a CanIt-Domain-PRO machine forwards mail to a back-end server that performs
SPF checks. For a description of SRS, please see http://en.wikipedia.org/wiki/
Sender_Rewriting_Scheme.
Sender’s Domain This is the domain part (everything after the @ sign) in the sender’s e-mail address.
Sendmail A UNIX-based program for sending and receiving e-mail. Sendmail is designed to route
mail from one mail server to another.
Spam Score A numerical score computed by CanIt-Domain-PRO that rates the likelihood that a message is spam.
Stream is a “virtual CanIt” machine offered by CanIt-PRO. If an incoming e-mail arrives for more
than one recipient, and the recipients each wish to have his or her own private spam quarantine,
CanIt-PRO re-mails the original message so each recipient has his or her own copy, and can
dispatch it as he or she sees fit.
Syslog A UNIX program that centralizes the logging of messages from various system daemons.
System Administrator is a user with administrative privileges in the base realm. The System Administrator is responsible for overall administration of the CanIt-Domain-PRO installation.
1.4. DEFINITIONS
25
Tempfail See “Temporary Failure Code”
Temporary Failure Code Also called tempfail, this is a code sent to a relay host telling it that e-mail
transmission has failed temporarily, and it should retry in a little while. Typically, the relay host
retains the e-mail message in a spool directory and retries transmission periodically. The host
eventually gives up after a certain period (typically, a few days) has elapsed without successful
transmission.
Ticker A CanIt-Domain-PRO program that runs periodic maintenance tasks.
Ticker Host In a CanIt-Domain-PRO cluster consisting of more than one machine, exactly one host
is designated to run the Ticker tasks. That host is called the Ticker Host.
Whitelist A list of domains, senders or hosts whose e-mail is permitted through without spamscanning.
26
Chapter 2
Operation
2.1
CanIt-Domain-PRO watches each incoming SMTP message and operates as follows. Because different recipients can have different settings, CanIt-Domain-PRO makes the following decisions at RCPT
time (once the recipient is known):
• If the SMTP connection is from a blacklisted host, the RCPT command is rejected.
• If the message sender is blacklisted (or the domain is blacklisted), the RCPT command is rejected.
• Otherwise, the message is collected and scanned.
After CanIt-Domain-PRO has scanned the message, it performs the following operations:
• Messages containing dangerous files (such as viruses) are discarded or rejected, depending on
which option you choose.
• If the sender, relay host or domain are whitelisted, the message is accepted without being
scanned for spam.
• Many spam-detection rules are applied to the message. If the message is judged not to be spam,
it is accepted and the SMTP transaction succeeds. Otherwise, CanIt-Domain-PRO will hold the
message locally.
For messages judged to be spam, CanIt-Domain-PRO takes the following steps:
• A unique ID is calculated by running the message body through a special hash function. The
hash calculation is designed to be resistant to some forms of trivial message modification.
• The ID is looked up in a database.
27
28
CHAPTER 2. OPERATION
1. If the ID is not found in the database, it is entered as a pending message. CanIt-DomainPRO will either hold a copy of the message locally or send a temporary failure code to the
SMTP sender, depending on how CanIt-Domain-PRO has been configured.
2. If the ID is in the database with status pending, CanIt-Domain-PRO may either save a
local copy or return a temporary failure code to the SMTP sender, depending on how
CanIt-Domain-PRO has been configured.
3. If the ID is in the database with status spam, a permanent rejection code is sent to the
SMTP sender.
4. If the ID is in the database with status not-spam, the message is accepted for delivery.
The flow of mail through CanIt-Domain-PRO is summarized in Figure 2.1. Note that this is the
conceptual flow; in reality, several optimizations are performed that would only complicate the figure.
See also Figures 2.2 on page 29 and 2.3 on page 31 for more accurate details about blacklisting and
whitelisting.
RCPT Command
End of DATA
Y
Blacklisted?
N
Reject
RCPT
Discard
Message
Y
Deliver
Message
Y
Hold
Message
N
Accept
RCPT
Whitelisted?
Proceed
to DATA
Y
Virus?
N
Looks
Like Spam?
N
Deliver
Message
Figure 2.1: Flow of Mail through CanIt-Domain-PRO
2.2
Interaction between Whitelists and Blacklists
CanIt-Domain-PRO must prioritize whitelists and blacklists. For example, suppose a sender is
whitelisted, but the host the message comes from is blacklisted. What should CanIt-Domain-PRO
do?
2.2. INTERACTION BETWEEN WHITELISTS AND BLACKLISTS
2.2.1
29
RCPT TO: Actions
At the SMTP RCPT TO: command, CanIt-Domain-PRO examines the envelope sender and SMTP
relay address, and makes decisions according to Figure 2.2.
Start
REJECT
Y
Invalid
Recipient?
Relay
Blacklisted?
Y
REJECT
Y
ALLOW
Y
REJECT
N
N
REJECT
Y
Sender
Blacklisted?
N
Relay
Whitelisted?
N
ALLOW
Y
Sender
Whitelisted?
N
Relay on
Reject RBL?
N
REJECT
Y
Domain
Blacklisted?
ALLOW
N
ALLOW
Y
Domain
Whitelisted?
N
Figure 2.2: RCPT TO: Decision
Here are the steps illustrated in Figure 2.2. They determine the response to the RCPT TO: command.
The first rule that matches returns the result; subsequent rules are not tested.
1. If the recipient is blacklisted, the command is rejected. Blacklisted recipients can never receive
e-mail.
30
2. If the recipient has opted out of spam-scanning, the command is accepted.
3. If the sender address is blacklisted, reject the command with an SMTP failure code.
4. If the sender address is whitelisted, accept the command. (That is, permit the SMTP transaction
to continue. The message may be rejected later for other reasons.)
5. If the domain of the sender is blacklisted, reject the command.
6. If the domain of the sender is whitelisted, accept the command.
7. If the sending relay’s IP address is blacklisted, reject the command.
8. If the sending relay’s IP address is whitelisted, accept the command.
9. If the sending relay is on a real-time blacklist for rejection, then reject the command.
10. Otherwise, accept the command.
2.2.2
Post-DATA Actions
After the SMTP “DATA” command has transmitted the entire message, CanIt-Domain-PRO has
enough information to determine a spam score. At this point, it makes decisions according to Figure 2.3.
2.2. INTERACTION BETWEEN WHITELISTS AND BLACKLISTS
31
START
Y
Virus Handling
Virus Found?
Accept Message
Y
N
Bad Attachment
Handling
Y
Y
Bad MIME type
or Extension?
Reject Message
Y
Y
Sender
Whitelisted?
Hold in Trap
Y
Y
Domain
Blacklisted?
"Hold"
RBL Rule?
Hold, Tag
or Reject
Domain
"Hold"?
Y
High Spam
Score?
N
Accept Message
N
Sender
Blacklisted?
Accept Message
Y
N
Hold in Trap
Y
N
N
N
Reject Message
Hold in Trap
N
N
Accept Message
Domain
Whitelisted?
Relay
Whitelisted?
N
Sender
"Hold"?
Reject Message
Y
N
Relay
Blacklisted?
N
Hold in Trap
Y
Relay
"Hold"?
N
Figure 2.3: Post-Data Decision
Here are the steps illustrated in Figure 2.3. They determine the response to the DATA command. The
first rule which matches returns the result; subsequent rules are not tested. (There is one exception:
If a “Hold Sender”, “Hold Domain” or “Hold Relay” rule is hit, but the message scores over the
auto-reject threshold, the message is rejected rather than held for review.)
When a message is “held in the quarantine”, the message will be held by CanIt-Domain-PRO for
review. To the sending SMTP relay, it appears as if the message was delivered successfully.
When a message is “rejected”, the sending relay receives an SMTP failure code. If the message being
rejected was held within CanIt-Domain-PRO, it is simply discarded.
When a message is “accepted”, it is simply delivered as usual.
1. If a virus was found in the message, then the action depends on the virus-handling setting.
Here’s what happens for the various settings:
• Hold/Tag – the message is held in the quarantine (or tagged in a tag-only stream.)
• Reject – the message is rejected with an SMTP failure code.
• Discard – the message is discarded. An SMTP success code is returned.
• Accept – processing continues to step (2) below.
32
2. If a bad MIME part or filename extension was found, then if the bad part has a “Reject” setting,
the message is rejected. Otherwise, the message is held in the quarantine (or tagged in a tag-only
stream.)
3. If the user has opted-out of spam-scanning, the message is accepted
4. If the sender is whitelisted, the message is accepted.
5. If the sender is blacklisted, the message is rejected. It may seem superfluous to check for a
blacklist here, given that the blacklist was checked during the RCPT command. However, by
the DATA command, we have the From: header, and CanIt-Domain-PRO applies sender checks
to the From: header adress also.
6. If the sender has a “Hold/Tag” setting, the message is held in the quarantine (or tagged in a
tag-only stream.) However, if it scores over the auto-reject threshold, it will be rejected.
7. If the domain is whitelisted, the message is accepted.
8. If the domain is blacklisted, the message is rejected. Again, at this point, CanIt-Domain-PRO
can make use of the From: header address.
9. If the domain has a “Hold/Tag” setting, the message is held in the quarantine or tagged. However, if it scores over the auto-reject threshold, it will be rejected.
10. If the relay is whitelisted, the message is accepted.
11. If the relay has a “Hold/Tag” setting, the message is held in the quarantine or tagged. However,
if it scores over the auto-reject threshold, it will be rejected.
12. If the relay is on a “Hold/Tag” real-time DNS blacklist, the message is held in the quarantine or
tagged.
13. If CanIt-Domain-PRO is in “Tag Only” mode, the message is tagged (if it looks like spam) and
accepted.
14. If the spam score is equal to or above the auto-reject threshold, the message is rejected. Otherwise, if the spam score is equal to or above the spam threshold, the message is held in the
quarantine.
15. Otherwise, the message is accepted.
2.3
Streaming
Because CanIt-Domain-PRO allows different recipients to have different spam-processing rules, an
incoming message for more than one recipient must be streamed.
The diagram in Figure 2.1 shows what happens to messages after they have been streamed. If an
incoming message arrives for more than one stream, copies are re-mailed to recipients in each stream,
and the original message is discarded. Then, each re-mailed message folows the flow in Figure 2.1,
with some minor differences that will be explained later.
2.4. HOW ADDRESSES ARE STREAMED
33
In Figure 2.1, all of the blacklisting and whitelisting decisions are unique to a stream. It is perfectly
feasible for one stream to whitelist a sender, a second stream to blacklist it, and a third stream to do
neither.
Messages that are streamed and re-mailed are not held by issuing a temporary-failure code, because
they would then reside in your own mail spool and waste resources during repeated sending attempts
(until they are approved or rejected.) Instead, held messages are stored in the database, and re-mailed
if approved or discarded if rejected.
2.4
How Addresses are Streamed
CanIt-Domain-PRO can map e-mail addresses to streams using the following techniques:
Database CanIt-Domain-PRO maintains a table of address-to-stream mappings in the Address Mapping Table. If you choose the Database technique, then this table is consulted to perform
the mapping. You hand-enter the mappings between addresses and streams. In addition, the
Database technique allows a “wildcard” lookup if the original lookup does not exist.
AsIs This method simply uses the entire e-mail address as the stream name, after stripping anglebrackets and converting to lower-case. Therefore, [email protected] gets mapped to
[email protected],
ChopDomain This method simply chops the domain part off the e-mail address.
[email protected] gets mapped to xzyyz.
Therefore,
ChopUser This method chops the user part off the e-mail
[email protected] gets mapped to example.com.
Therefore,
address.
Program This method runs the account-info program to determine the stream. Please see Section 7.2.4 on page 149 for details.
User Lookup You can create so-called “User Lookups” that permit you to use LDAP or arbitrary
scripts to map addresses to streams. These are described in Section 7.2.
Note:
No matter what stream method you choose, an exact-match database lookup is always done first. This
lets you override the mapping for special cases. For example, if you host only a single domain, then
the ChopDomain method is probably fine for most addresses. However, if you also host mailing
lists, you’d like to stream spam for the lists to the mailing list owners. In that case, you can add
special mappings mapping [email protected] to joe-owner, (where joe-owner is
the person responsible for list-name.)
Because the Program method is somewhat inefficient, CanIt-Domain-PRO caches results in the
database table. This improves efficiency while retaining flexibility. By default, cached entries are
valid for 24 hours, but you can adjust the timeout.
34
2.5
How Streaming Methods are Chosen
Each domain can be streamed using its own method. To select a streaming method, CanIt-DomainPRO first looks up the domain in the Domain Mapping Table. This table holds a list of streaming
methods for each domain. If the lookup fails, CanIt-Domain-PRO looks up the wildcard entry “*” in
the Domain Mapping Table and uses that method to stream the address.
Figure 2.4 illustrates how addresses are streamed.
2.5. HOW STREAMING METHODS ARE CHOSEN
Incoming Mail for
[email protected]
35
stream = lookup
"[email protected]" (followed
by "user@*" if not found)
in Address Mapping Table
method = lookup
"example.com" in
Domain Mapping Table
stream found?
Y
N
method found?
Y
method =
ChopDomain
ChopUser
or AsIs?
N
method = lookup
"*" in
Domain Mapping Table
Y
N
method = "Database"
stream = adjust address
N
method =
Program?
method found?
Y
Y
Run account−info script
to determine
local user
Y
Look up stream
in LDAP directory.
Cache stream in
Address Mapping
Table
N
method =
LDAP
N
stream = lookup
"*@example.com" in
Address Mapping Table
stream found?
Y
N
stream = lookup
"*" in
Address Mapping Table
stream found?
Y
N
stream = "default"
Figure 2.4: Address Streaming
Return stream
36
Figure 2.4 looks complicated, but the streaming process is very flexible, and actually quite simple.
Here is a description of the figure, with some more details that would crowd the figure too much.
1. For an incoming message to [email protected], CanIt-Domain-PRO first looks up example.com in the Domain Mapping Table. If that lookup succeeds, CanIt-Domain-PRO will have
a method (ChopDomain, ChopUser, Program, Database or a user-lookup name), and CanItDomain-PRO proceeds to Step 4.
2. If the lookup fails, the leading component of the domain name is dropped (ie: “subdomain.example.com” becomes “example.com”) and we retry Step 1 with the shorter name.
3. If lookups on all domain components fail, CanIt-Domain-PRO looks up * in the Domain Mapping Table. This allows you to set a default streaming method for all domains. If that lookup
fails, the method defaults to Database.
4. Regardless of the method chosen, CanIt-Domain-PRO looks up [email protected] in the Address Mapping Table. If an exact match is found (and it is not expired if it is a cached entry),
the result of that lookup is used as the stream. If the exact match is not found, but a wildcard
user@* is found in the Address Mapping Table, the result of that lookup is used as the stream.
5. Otherwise, CanIt-Domain-PRO determines the stream as follows:
• If the method is ChopDomain, the @example.com part is deleted, and the stream becomes
user.
• If the method is ChopUser, the user@ part is deleted, and the stream becomes example.com.
• If the method is AsIs, the entire e-mail address [email protected] is used as the stream
name.
• If the method is Program, CanIt-Domain-PRO runs the account-info program as
described in Section 7.2.4.
• If the method refers to a user-lookup, then the user-lookup is invoked to determine the
stream. See Section 7.2 for details.
If the stream determination succeeded (AsIs, ChopDomain and ChopUser always succeed;
Program fails if the program produces no output), then the stream is returned. Additionally, the
stream may be cached in the Address Mapping Table.
6. If the previous step failed to determine a mapping method, or the method was set to Database,
CanIt-Domain-PRO looks up *@example.com in the address mapping table. This allows you to
map all addresses in a particular domain to a stream. If that fails, as a last resort, CanIt-DomainPRO looks up * in the address mapping table. If that final lookup fails, then a special stream
named default is used.
2.6
Status of Messages
Every message in the database has one of three statuses. The status names and their meanings are:
2.7. THE DATABASE
37
pending Messages enter pending state when they arrive, and remain there until they are marked as
spam or nonspam. These messages are displayed in the Web-based “Pending Messages” list.
spam The spam-control officer can mark a message as spam. If a message marked as spam is received, a rejection notice is sent to the sending mail server, and the message is not delivered.
not-spam The spam-control officer can mark a message as not-spam. If a message marked as notspam is received, it is delivered as usual.
2.6.1
Secondary MX Relays
Many organizations have secondary MX hosts that queue mail if the primary host is down. They then
relay the queued mail when the primary MX host comes back up. Ideally, CanIt-Domain-PRO should
run on all of your MX hosts. However, if it can only run on your primary MX host, then all other MX
hosts should relay to the CanIt-Domain-PRO machine. You should then tell CanIt-Domain-PRO the IP
addresses of the secondary MX hosts via the “Known Networks” facility so that CanIt-Domain-PRO
can use the Never Tempfail handling for messages from thoses hosts. (There is no point in keeping
mail queued and retransmitted on your secondary MX hosts; it’s better to accept and hold the message
on the CanIt-Domain-PRO machine.)
2.7
The Database
The incident database is key to the correct operation of CanIt-Domain-PRO. Three different agents
operate on the database as shown in Figure 2.5:
CanIt Filter
Web−Based
GUI
Periodic Jobs
Incidents
Database
Figure 2.5: Database Agents
The agents operating on the database are:
• The CanIt-Domain-PRO Filter – This is the portion of CanIt-Domain-PRO that integrates with
Sendmail and disposes of spam messages.
38
• The Web-Based GUI – This is used by users or administrators to mark messages as spam or
legitimate. The Web-Based GUI also lets you monitor the levels of spam and take action against
specific senders, domains or relay hosts.
• Periodic Jobs – These housekeeping jobs perform operations like moving expired pending messages into spam status and purging very old messages from the database. Periodic jobs may be
started from one of two places:
1. The /usr/share/canit/scripts/canit.cron script, which should be run once
a night.
2. As part of the operation of the CanIt-Domain-PRO daemon (canitd). Canitd is a daemon
that starts on bootup and runs continuously, performing background maintenance tasks.
2.8
Remailing Messages
On occasion, CanIt-Domain-PRO will be forced to remail a message after discarding the original. The
following scenarios cause remailing:
1. If a message comes in for recipients in more than one stream, CanIt-Domain-PRO generates one
new copy for each stream and mails out the copies. The original message is then discarded. You
may see a message in the log file indicating that the message has been discarded; don’t panic.
The copies are safely queued.
2. If a Pending message is held in the database and subsequently approved for release, CanItDomain-PRO fetches the message body from the database and remails it. This always takes
place on the designated ticker host, no matter which host processed the original message.
In all cases when CanIt-Domain-PRO remails a message, the message goes into Sendmail’s
submission queue (most likely in the queue directory /var/spool/clientmqueue or
/var/spool/mqueue-client. The message is only processed on the next run of the submission queue. For this reason, you should keep the submission queue interval short (on the order of a
minute or two.) On CanIt-Domain-PRO appliances, the submission interval is automatically configured for you. On other platforms, consult your system’s documentation for details on how to shorten
Sendmail’s submission queue interval.
Chapter 3
Realms
3.1
Introduction to Realms
CanIt-Domain-PRO has three levels of administrative control:
1. The System Administrator administers all aspects of CanIt-Domain-PRO and is responsible for
setting up and provisioning the system.
2. A Realm Administrator administers settings and rules for a given realm. A realm encompasses
one or more Internet domains. The realm administrator is responsible for provisioning streams
within his or her realm. A realm administrator is said to have root privileges within a realm.
3. A Stream Owner administers settings and rules for his or her own stream. A stream owner
is typically an end-user or a person responsible for administering a small group of e-mail addresses.
The administrative levels are illustrated in Figure 3.1 below:
System Administrator
Realm 1
Realm 2
Realm Administrator
Realm N
Realm Administrator
Stream 1
Stream Owner
Realm Administrator
Stream N
Stream Owner
Stream 1
Stream Owner
Stream N
Stream Owner
Figure 3.1: Administrative Levels
39
40
CHAPTER 3. REALMS
3.2
Realm Names
A realm name can consists only of letters, numbers, dashes and underscores. That is, only the following characters can appear in a realm name:
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
a b c d e f g h i j k l m n o p q r s t u v w x y z
0 1 2 3 4 5 6 7 8 9 0 Realm names are case-sensitive; a realm named REALM-ONE is different from realm-one.
3.2.1
The base Realm
The realm named base is special. This realm always exists and cannot be deleted. Any user with
root privileges in the base realm is considered an overall CanIt-Domain-PRO system administrator,
and can access any realm and setting.
In other words, a realm administrator of the base realm is an overall CanIt-Domain-PRO administrator.
3.3
Note:
Creating Realms
This section describes features that only the CanIt-Domain-PRO System Administrator can use.
Click on Setup and then Realms. The Realm Screen appears:
Figure 3.2: Realm Screen
To create a realm:
1. Enter the realm name in the Realm box.
2. Enter a short description in the Description box.
3.4. REALM MAPPINGS
41
3. If you wish to enter an expiry date, do so in the Expiry box. See Section 3.6 for details about
realm expiry.
4. Normally, all realms you create have the base realm as a parent realm. If you wish to set a
realm’s parent to something else, select a realm name from the Parent pull-down mennu. See
Section 3.7 for details about realm hierarchy.
5. Click Submit Changes.
To delete a realm:
1. Enable the Delete? checkbox for the realm you wish to delete.
Note that it is not possible to delete the base realm.
3.4
Note:
Realm Mappings
Only the CanIt-Domain-PRO System Administrator can create new realm mappings. Realm administrators can delete realm mappings (irrevocably) or remap a domain from one realm to another.
To associate a domain with a realm, CanIt-Domain-PRO uses a Realm Mapping Table. To access this
table, click on Setup and then Realm Mappings. The Realm Mappings screen appears:
Figure 3.3: Realm Mappings
In this example, the domains roaringpenguin.com and roaringpenguin.ca are both
mapped to the roaringpenguin realm, while artandframingsolutions.com is mapped
to afs. If CanIt-Domain-PRO accepts mail for other domains, then they will be mapped to the base
42
CHAPTER 3. REALMS
realm. Any domain without an explicit realm mapping will be mapped to base. (The rules for realm
mapping are summarized in Section 3.5.)
To add a realm mapping:
1. Enter the domain name in the Domain box.
2. Select the realm name in the Realm box. Note that you must create realms before you can add
mappings to them.
To delete a realm mapping:
• Enable the checkbox next to the mapping you wish to delete.
• Click Submit Changes.
3.5
Determining the Realm
CanIt-Domain-PRO determines the realm for e-mail addresses and user names as follows:
3.5.1
Mapping an Address to a Realm
1. Given an e-mail address of the form [email protected], CanIt-Domain-PRO looks up the
domain (domain.com) in the Realm Mapping Table and uses the realm found in the table.
2. If no realm was found in Step 1, the address is placed in the base realm.
Note:
The addresses postmaster, postmaster@localhost and postmaster@machine name
are always mapped to the base realm, no matter what. (Here, machine name is the name of the
host processing the email.)
3.5.2
Mapping a Login Name to a Realm
1. If a user’s login name is of the form [email protected], then CanIt-Domain-PRO uses the
procedure described in Section 3.5.1 to determine the realm.
2. If a user logs in with a name of the form realm:user, then CanIt-Domain-PRO uses realm
as the realm name.
3. Otherwise, CanIt-Domain-PRO uses the default realm as configured in the
site/config.php configuration file. If no default realm is set in that file, then
CanIt-Domain-PRO uses base as the realm name.
3.6. REALM EXPIRY
3.6
43
Realm Expiry
When you create a realm, you can set an expiry date. Whenever the realm administrator logs in to
CanIt-Domain-PRO, he or she will receive a warning starting 30 days prior to the expiry date. If you
are hosting CanIt-Domain-PRO realms on behalf of third-parties, this is a good way to remind them to
renew their subscription. The expiry date normally has no other effect (in particular, CanIt-DomainPRO will continue filtering mail as usual after the expiry date) and is intended only as a renewal
reminder. If you do not set an expiry date, then the realm never expires.
3.6.1
Suspending Service to a Realm
While the expiry date field normally has no effect, if you set the expiry to the “magic” date
1990-01-01, then all service to the realm is suspended. What this means is:
• No users in that realm will be able to log in.
• All mail to anyone in the realm will be permanently rejected with a “Service suspended” error
message.
Suspending service to a realm is a drastic step since it causes all mail to bounce. Please use it only as
a last resort.
3.7
Realm Hierarchy
Realms normally have the base realm as their parent. However, if you are reselling CanIt-DomainPRO services to others who wish to have their own set of realms for their customers, you can create
a realm hierarchy. A realm administrator has access to his or her own realm and all realms under it.
Consider Figure 3.4:
44
CHAPTER 3. REALMS
base
cust−1
cust−2
subcust−2−1
subcust−2−2
subcust−2−1−1
Figure 3.4: Realm Hierarchy Example
In the example in Figure 3.4, the parent of cust-1 and cust-2 is base. The parent
of subcust-2-1 and subcust-2-2 is cust-2, and the parent of subcust-2-1-1 is
subcust-2-1.
• The administrative user in the base realm can access all realms.
• The administrator in cust-1 can only access the cust-1 realm.
• The administrator in cust-2 can access subcust-2-1,
subcust-2-1-1.
subcust-2-2 and
• The administrator in subcust-2-1 can access subcust-2-1 and subcust-2-1-1.
• The administrator in subcust-2-2 can only access subcust-2-2.
• The administrator in subcust-2-1-1 can only access subcust-2-1-1.
In the Realms screen (Figure 3.2), click on Tree View to see a hierarchical view of the realms. You
can restrict the view to a subtree of the entire hierarchy by selecting the root of the tree from the Tree
root pull-down menu.
3.8
Realm Custom Fields
CanIt-Domain-PRO allows you to create up to four custom fields so you can associate various pieces
of information with a realm. For example, you may wish to include a customer number with each
realm. To configure custom fields, click on Setup and then Realms. In the realm display, click on
Custom Fields. The Custom Fields screen appears:
3.8. REALM CUSTOM FIELDS
45
Figure 3.5: Realm Custom Fields
To create custom fields:
1. Enter the name of the field in the Name box.
2. If you wish to have the field displayed specially, enter a format string in the Format box. This
string must contain exactly one %s sequence; this will be replaced by the value of the custom
field. In the example in Figure 3.5, Custom Field 2 (AccountID) will be displayed as a hyperlink,
presumably to an accounting system.
3. Click Submit Changes to make the changes take effect.
Any custom fields you create are displayed as additional columns in the Realms screen (for the CanItDomain-PRO administrator only!). To remove a custom field, simply make the Name column blank.
46
CHAPTER 3. REALMS
Chapter 4
Streams
4.1
Introduction to Streams
The stream is a central concept in CanIt-Domain-PRO. Understanding streams is essential to understanding CanIt-Domain-PRO. Please be sure to read this chapter before configuring a production
CanIt-Domain-PRO server.
4.2
Realms
A realm is a collection of Internet domains, all of whose anti-spam settings and quarantines are provisioned by a Realm Administrator. Within a realm, there may be many streams. Two streams with the
same name can coexist in different realms; CanIt-Domain-PRO will consider them to be two different
streams.
4.3
The Definition of a Stream
A stream is a collection of rules and policies. Each stream in CanIt-Domain-PRO can have its own
rules, settings, thresholds and policies.
Associated with each stream is a quarantine. A quarantine consists of messages that have been held
based on the streams settings. For example, a message can be held because of its spam score, or
because it contains a suspicious MIME type.
4.4
Users and E-Mail Addresses
Under many circumstances, a single e-mail address corresponds to a single user. For example, the
e-mail address [email protected] corresponds to the single user dfs.
However, most mail setups are more complicated than this. The first complication comes from
aliases. For example, the user dfs may have, in addition to his normal e-mail address, aliases
47
48
CHAPTER 4. STREAMS
like [email protected] and [email protected]. We would most
likely want the same settings and policies to apply to all three aliases.
Another complication comes from list addresses.
For example, the e-mail address
[email protected] does not correspond to any particular user. Instead, it is a list
alias that expands to several users. It might make sense to have a separate set of policies for sales
than for real users, or it might make sense to assign the policies used by one of the recipients on the
sales list.
As we see above, the mapping between users and e-mail addresses is not simple. A single e-mail
address may result in delivery to several users (the sales example), or a single user may have several
e-mail addresses that all deliver to the same place (the aliases example.)
Streams were created to give you the flexibility of assigning policies. They act as an intermediate
container between e-mail addresses and actual users, and let you assign policies any way you choose.
As an example, consider Figure 4.1:
4.4. USERS AND E-MAIL ADDRESSES
E−Mail Address
49
Stream
User−ID
[email protected]
[email protected]
dfs
dfs
paul
paul
[email protected]
[email protected]
[email protected]
(a)
E−Mail Address
Stream
User−ID
[email protected]
[email protected]
dfs
dfs
[email protected]
[email protected]
[email protected]
sales
paul
paul
(b)
Figure 4.1: Streaming Scenarios
Note that streaming affects only how CanIt-Domain-PRO directs mail for rule and quarantine purposes. Streaming does not alter the ultimate delivery address; normally, CanIt-Domain-PRO delivers
50
CHAPTER 4. STREAMS
mail to the back-end server without altering recipient addresses at all.
We assume that there are two users, dfs and paul. We assume that dfs has the three aliases shown,
and that the sales address actually gets delivered to both dfs and paul.
In Figure 4.1(a), all mail for dfs’s aliases go into the dfs stream. Mail for paul goes into the paul
stream. Furthermore, mail for sales also goes into paul. Although mail for sales is delivered to
two users, all of the settings and policies are controlled by the paul stream, and paul is responsible
for clearing the quarantine.
In Figure 4.1(b), sales has its own stream. It can thus have different settings and rules from either
paul or dfs. Furthermore, both paul and dfs are given access to the stream, so either of those
users can adjust the settings and check the quarantine for sales.
4.5
Mapping
When e-mail comes in, each recipient address is mapped to a stream. We call this process address
mapping. Once the stream is determined, CanIt-Domain-PRO knows which settings and rules to apply
for that recipient. The process by which CanIt-Domain-PRO maps addresses to streams is illustrated
in Figure 2.4 on page 35.
An e-mail address is mapped to a stream in a three-step process:
1. The domain part of the address (everything after the “@” sign) is looked up in the Realm Mapping Table. This lookup determines the realm to which the address belongs.
2. The domain part of the address is looked up in the Domain Mapping Table. This lookup
results in a method by which to map the address to a stream.
Note that CanIt-DomainPRO looks up the mapping method using a combination of the realm (determined in step
1) and the domain. The combination of realm and stream determined in this step is written
realm name:stream name
3. Once the method has been determined, then the address is mapped to a stream using the appropriate method. Details are in Section 5.14 on page 81.
Note:
If there is an exact match for an email address in the Address Mapping Table (under Setup :
Address-to-Stream Mappings) then it is always used, overriding any mapping method. Furthermore, if there is no exact match, but there is an entry for user@*, then that entry too is
used, overriding any mapping method.
4.6
The Home Stream
When a user logs in to the Web interface, CanIt-Domain-PRO must associate a stream with the user
name. By default, CanIt-Domain-PRO chooses a stream with the same name as the user’s login—this
is called the home stream. For example, the user dfs would automatically be sent to the stream dfs
upon login. However, it is possible to give users access to additional streams, and to change the default
4.7. THE “DEFAULT” STREAM
51
login stream. Also, it is possible to change the user’s home stream with the account-info script
(Section 7.2.4).
Note:
Stream names are case-sensitive. Thus, a stream called dfs is completely separate from a stream
called DFS.
4.7
The “default” Stream
CanIt-Domain-PRO treats the stream named default specially in several ways:
• When the database initialization script runs, it sets the login stream for the CanIt-Domain-PRO
administrator to default.
• If a stream mapping cannot be found for an address, the address is mapped to default.
• Any blacklists, whitelists and rules defined in the default stream are inherited by all other
streams. (However, stream owners can turn this inheritance off if they wish.) Note that in
CanIt-Domain-PRO, rules for a stream example-stream in realm example-realm are
searched up through the realm hiearchy.
1. Search for the rule in example-realm:example-stream.
2. If not found, search in example-realm:default.
3. If not found, serach in example-realm’s parent realm in the default stream. Continue looking up the realm hierarchy until base:default is reached.
52
CHAPTER 4. STREAMS
Chapter 5
CanIt-Domain-PRO Setup
5.1
Accessing The Web Interface
Using your Web browser, open the URL where you installed the CanIt-Domain-PRO web pages.
For example, if your server is mailserver.mydomain.com and you installed the GUI in the
directory canit under your Apache document root, the URL to open would be:
http://mailserver.mydomain.com/canit/
(By default, our binary packages and our Debian-based appliances put the web pages at
http://machine.yourdomain.net/canit/)
5.1.1
License Key Screen
The very first time you log in, you will see the License Key Screen (Figure 5.1):
Figure 5.1: License Key Screen
Enter or cut-and-paste your license key into the entry box and click Submit Key. The license key
includes all the text starting from License and continuing to the end of the string of letters and
numbers after Check=.
53
54
5.1.2
CHAPTER 5. CANIT-DOMAIN-PRO SETUP
Login Screen
Once the license key has been entered, navigating to the CanIt-Domain-PRO URL reveals the Login
Screen (Figure 5.2):
Figure 5.2: Login Screen
Log in using the name and password you selected when you initialized the CanIt-Domain-PRO
database. (See Section J.1 on page 353 if you’ve forgotten the password.)
In the Installation Guide example, we used “admin” and “secret”. If you have a CanIt-Domain-PRO
appliance, the defaults are “admin” and “canit”. (Naturally, you should change the password before
connecting your CanIt-Domain-PRO appliance to the Internet!)
Normally, CanIt-Domain-PRO will set a session cookie in your browser. This means that if you close
your browser, your session will automatically end. If you want CanIt-Domain-PRO to remember your
session even if you close the browser, enable the “Remember Me” checkbox. This puts a cookie that
lasts longer (by default, 7 days) on your computer. Do not use the “Remember Me” option on a public
computer; you should only use it on a workstation to which you alone have access.
Once logged in, you should see the CanIt-Domain-PRO welcome screen:
5.2. THE SETUP MENU
55
Figure 5.3: Welcome Screen
5.2
The Setup Menu
The Setup main menu entry contains sub-entries for various parts of basic CanIt-Domain-PRO setup.
Under the Setup menu, you will find:
• Wizards – a collection of tools for easily configuring certain common scenarios.
• License Key – a page to enter your CanIt-Domain-PRO license key.
• Verification Servers – a table allowing you to check recipients against internal servers before
CanIt-Domain-PRO will accept them.
• Known Networks – a table allowing you to change aspects of CanIt-Domain-PRO behavior for
mail originating from certain known networks.
• Features – a page allowing you to turn off certain CanIt-Domain-PRO functionality to improve
performance.
• System Check – a page that performs a few simple “sanity checks” on your CanIt-Domain-PRO
system.
• Templates – a page for configuring templates that control how CanIt-Domain-PRO appends
Bayesian voting information to e-mail and the format of Pending Message Notifications.
• Theme Customization – a page for customizing the CanIt-Domain-PRO “look”. Can be used
to brand CanIt-Domain-PRO.
• Domain Routing – a page for configuring e-mail routing. Please note that this link is available
only on Debian-based appliaces or on RPM installations with the appliance RPMs installed.
• HTTPS – a page for configuring HTTPS. Please note that this link is available only on Debianbased appliances. (It is not available on RPM or source installations.)
56
• Cluster Management – a page for viewing and managing cluster members.
• Domain Mappings and Address Mappings – two tables that tell CanIt-Domain-PRO how to
convert an e-mail address to a stream.
• Authentication Mappings and User Lookups – pages for integrating CanIt-Domain-PRO with
external directories or authentication mechanisms. These are fully described in Chapter 7.
5.3
Note:
Wizards
The Wizards menu item allows you to ease CanIt-Domain-PRO setup by using a wizard to speed
through choosing some basic settings. The available wizards are shown on the Setup page. The
wizards are self-documenting and guide you through the steps required to configure CanIt-DomainPRO. However, the following wizards are important enough to warrant mention:
5.3.1
Basic Setup Wizard
The Basic Setup Wizard helps you set some basic settings essential to the operation of CanIt-DomainPRO. On a new CanIt-Domain-PRO installation, you should follow the steps in this wizard to set some
basic settings to sensible values. It is important not to operate CanIt-Domain-PRO until you have
worked through the Basic Setup Wizard.
5.3.2
RPTN Setup Wizard
The RPTN Setup Wizard configures RPTN, the Roaring Penguin Training Network. (RPTN is a
mechanism for sharing Bayes data to increase scanning accuracy. See Section 8.5 on page 154 for
details.)
5.3.3
Note:
Dictionary Attack Detection Wizard
Dictionary Attack Detection works only on Linux.
A Dictionary Attack is an attack whereby an attacker tries to send mail to hundreds or thousands of
different e-mail addresses within a domain in the hopes of discovering some valid addresses. CanItDomain-PRO (on Linux only) can react to dictionary attacks by blocking them using kernel firewall
rules.
To enable dictionary-attack detection:
1. Click on Setup : Wizards and then Dictionary Attack Detection Wizard.
2. Select Yes when asked “Would you like to enable the dictionary-attack detector?” Click Next.
3. Adjust the parameters as follows:
5.4. VERIFICATION SERVERS
57
• Time span over which to track bad recipients specifies for how long CanIt-DomainPRO will keep history. For example, if you specify 900 seconds, then CanIt-Domain-PRO
tracks bad recipients over the last 15 minutes.
• Number of bad recipients to trigger firewalling specifies how many bad RCPT commands a host must issue (within the tracking time) to be firewalled off. Continuing the
example, if you specify 5 for this parameter, then any host that issues 5 invalid RCPT
commands within 900 seconds will be firewalled off.
• Length of time in seconds to remain firewalled specifies how long a host remains firewalled once CanIt-Domain-PRO decides it is an attacker. The default is 3600 seconds (one
hour.)
4. Click Next
5. Review your settings and click Finish to make them take effect.
You may wish to exclude certain hosts from ever being banned because of bad RCPT commands. You
can exclude such hosts by adding them to the Known Networks list (Section 5.7) with the Omit from
Dictionary Attack Detection flag set.
Note:
When a host is firewalled off, the Sendmail process that triggered the firewall rule will not receive any
traffic from the host. By default, Sendmail will wait one hour between commands. This is far too long
if you use the dictionary-attack detector; we recommend shortening Sendmail’s Timeout.command
parameter to 5 minutes or shorter. On CanIt-Domain-PRO appliances, this configuration change has
been done for you. On other platforms, include the line:
define(‘confTO COMMAND’, ‘5m’)dnl
in your sendmail.mc file and rebuild sendmail.cf.
5.4
Verification Servers
If CanIt-Domain-PRO acts as a filtering server that always forwards mail on to other machines, you can
have it check recipient addresses against other machines. The internal machine that verifies recipient
addresses is called a Verification Server. The mechanism is illustrated in Figure 5.4:
1
2
RCPT TO:<[email protected]>
RCPT TO:<[email protected]>
4
Scanner
Response: 250 OK / 550 No User
3
Response: 250 OK / 550 No User
Verification Server
Figure 5.4: Verification Server Operation
The sequence of events in Figure 5.4 is as follows:
1. An external SMTP server sends the command: RCPT TO:<[email protected]>
58
2. Before CanIt-Domain-PRO accepts the RCPT command, it starts an SMTP session with the
Verification Server (sending a HELO and MAIL command first) and sends the same RCPT
command to the Verification Server.
3. The Verification Server responds to the CanIt-Domain-PRO scanner with a reply code.
4. The CanIt-Domain-PRO scanner responds to the external server with the same response it received from the Verification Server.
Note:
This feature only works if the internal machines fail RCPT commands for unknown users. That is, the
internal machine must be configured to reject unknown recipients during the SMTP transaction. Some
SMTP servers accept any recipient address and then later on generate a failure notification. Servers
that delay the rejection of invalid addresses in this manner will not work as Verification Servers.
Versions of Microsoft Exchange prior to Exchange 2003 will not work as verification
servers. Recent Exchange versions can be configured to reject unknown recipients during the
SMTP transaction. See the instructions linked from http://www.roaringpenguin.com/
recipient-verification for your version of Exchange.
In all cases, you should disable all other Exchange anti-spam features including tarpitting. (Tarpitting
is a completely useless technology for a server behind a spam filter and serves only to slow down
CanIt-Domain-PRO.) Make sure that the only anti-spam feature enabled on the Exchange server is
recipient filtering.
CanIt-Domain-PRO allows you to enter a list of domains and the machines that will verify mail for
the domains. (Note that this does not change your Sendmail configuration; you need to ensure that
Sendmail’s mailertable routes mail appropriately.)
To edit the verification server list, click on Setup and then Verification Servers. The following page
appears:
Figure 5.5: Verification Servers
In this example, CanIt-Domain-PRO performs the following checks:
• Any recipient whose domain is blacky.roaringpenguin.com is verified against the machine blacky.roaringpenguin.com
• Any recipient whose domain is canit.ca is verified against the machine mail.canit.ca
5.4. VERIFICATION SERVERS
59
• Any recipient whose domain is roaringpenguin.com is verified against the machine
mail.roaringpenguin.com
To add a domain/server pair to the table:
• Enter the domain name in the Domain box and the server name or IP address in the Server
box. Note that you can enter multiple verification servers in the Server box by separating the
names or addresses with commas. If you enter multiple servers, CanIt-Domain-PRO tries them
in order until it receive a definite positive or negative response.
• Sometimes, your verification server may be down or unreachable. There are three approaches
to deal with this situation:
– If you would like CanIt-Domain-PRO to tempfail the mail, set Action if Unavailable to
“Tempfail”.
– If you would like CanIt-Domain-PRO to queue mail to addresses that have been proven
valid in the last 60 days, set Action if Unavailable to “Queue Seen Addresses”. This is
the recommended setting and is the default.
– If yo would like CanIt-Domain-PRO to queue all mail (even if the recipients have not
been proven valid), set Action if Unavailable to “Queue All Addresses”. Note: This
setting runs the risk of causing backscatter and is not recommended.
• Click Submit Changes
To delete a domain/server pair from the table, enable the appropriate Delete checkbox and click Submit Changes.
If you enter a string in the “Filter:” box, then CanIt-Domain-PRO limits the display to entries whose
Domain or Server columns contain that string.
If your verification server listens on a non-standard port (that is, a port other than port 25), you
may specify the port number by following the server name with a slash and the number. For example, if you have a server called mail.example.com that listens on port 2525, you can use
mail.example.com/2525 in the Server column.
Note:
If you use a verification server, ensure that the server does not throttle or rate-limit the CanIt-DomainPRO server in any way. Because CanIt-Domain-PRO runs an SMTP connection for each RCPT command, some naive SMTP server software may think it’s under attack and rate-limit the CanIt-DomainPRO server, with disastrous results.
5.4.1
Wildcard Verification Server
You may optionally choose to add a Verification Server entry for the wildcard domain of ’*’. This will
cause mail for any domain that does not have a specific entry to be checked against that server.
Note:
If you are relaying outbound mail via your CanIt-Domain-PRO server, you should NOT use a wildcard verification entry, as it will likely result in the rejection of all outbound mail. You can avoid this
60
problem by forcing outbound mail through a different realm than inbound mail; in this way, the inbound realm’s verification server settings are not used for outbound mail. The outbound realm may be
a subrealm of the inbound realm if you wish to provide administrative access to the inbound realm’s
administrator.
Finally, note that Verification Server lookups are made only on CanIt-Domain-PRO cluster members
that are marked “Inbound” in the Cluster Members Table. (Normally, all CanIt-Domain-PRO nodes
are marked “Inbound”.)
5.4.2
SRS and Verification Servers
CanIt-Domain-PRO will rewrite the envelope sender using SRS before checking against a Verification
Server if all of the following conditions are met:
1. SRS has been configured.
2. The sending address SPF lookup resulted in “pass”.
3. The quarantine setting “Enable SRS” is set to true in the default stream of the recipient’s realm.
The reason CanIt-Domain-PRO looks in the default stream is that address-to-stream mapping
is normally only done after a recipient address has been verified.
5.5
Note:
Mail Routing
This section is applicable only to Hosted CanIt, to Debian-based CanIt-Domain-PRO appliances or to
Red Hat installations with the appliance RPMs installed. On other CanIt-Domain-PRO installations,
you need to configure routing manually by editing Sendmail’s access and mailertable files.
Please note the following important requirement:
All of the features in Sections 5.5 through 5.6 rely on SSH to operate. Your system must be running
an SSH server listening on port 22 and it must allow public-key authentication. If you are running a
cluster, all cluster members must be running an SSH server on port 22 and permit connections from
all other cluster members. If your SSH server listens on a different port, the features will not work.
To configure mail routing, click on Setup and then Domain Routing. The Domain Routing page
comes up:
Figure 5.6: Domain Routing Screen
5.5. MAIL ROUTING
61
Note that the Domain Routing page shows the routing for all domains in the current realm and in all
of its subrealms.
To add a domain for routing:
1. Enter the domain name in the “Domain” box.
2. Click Add Domain
The Domain Routing Detail screen will come up:
Figure 5.7: Domain Routing Detail
1. Enter the servers to which mail should be routed for the given domain. You can enter more than
one server; if you need more than one, enter them one per line. The servers are tried in order,
until one successfully accepts or permanently rejects the mail.
2. If you wish the routing server(s) to be treated as MX records, set Treat route entries as MX
records to Yes. Otherwise, leave it at No.
Note:
You should normally not treat your route entries as MX records. Unless you know for sure that
they specify correct MX records that will route your mail correctly, setting this setting to Yes
could cause mail loops. If you use IP addresses rather than host names for your routes, you must
not set Treat route entries as MX records to Yes.
3. If you wish to route mail to a non-standard port (normally, SMTP traffic goes to TCP port 25),
enter the port number in the Destination TCP port box. Note that only the CanIt-Domain-PRO
site administrator can specify a port that is less than 1024 and that is not 25 or 587.
Note:
CanIt-Domain-PRO imposes a system-wide limit of 12 different non-standard TCP ports. This
limit is caused by technical limitations in Sendmail and cannot be raised. Again due to Sendmail
technical limitations, if you specify more than one server in the Route To list, all servers must
listen on the same port.
Note:
If you use a non-standard port for mail routing and are using the Verification Servers feature to
validate recipients, you may need to specify the same non-standard port in Setup : Verification
Servers.
62
4. CanIt-Domain-PRO can send an alert when either the number of queued messages or the age of
the oldest queued message exceeds a threshold. The Number of queued messages required
to trigger notification and Age of queued message in hours required to trigger notification
settings control when warnings are sent. In order to have alerts generated, you must enter an
email address in the Notification Email Address field, and this address cannot be in the same
domain as the domain being routed. (If mail for example.org is backing up in the queue, it
is probably pointless to attempt to mail an alert to someone in that domain.)
If you wish to send an alert to more than one recipient address, enter a comma-separated list of
email addresses. For example:
[email protected], [email protected]
5.5.1
Outbound Relaying
Normally, CanIt-Domain-PRO refuses to relay mail for domains that do not appear in the Domain
Routing Screen. However, if you wish to relay outbound mail through CanIt-Domain-PRO, you can
specify networks for which relaying should be enabled. To do this:
1. Click on Setup and then Known Networks
2. Enter the network from which relaying should be allowed. For example, to allow all machines
on the Class C network 192.168.2.0 to relay outbound mail, enter 192.168.2.0/24
3. Enable the Allow Relaying checkbox.
4. Click on Submit Changes.
5.5.2
Outbound Relaying for Select Domains
Normally, CanIt-Domain-PRO enables the Relay Unlisted Domains (rud) flag for a Known Network.
This means that if Allow Relaying is enabled, then mail from the given network is relayed regardless
of the sending domain.
If you wish to relay mail from a network only for specific domains, perform the following steps:
1. Click on the Show button in the Associated Domains column corresponding to the appropriate
Known Network.
2. Enter a domain in the “Add Domain” text box and click Submit Changes
3. Repeat the previous step for all sending domains that should be relayed from the given network.
4. Disable the Relay Unlisted Domains flag.
5.6. CLUSTER MANAGEMENT
5.6
63
Cluster Management
The CanIt-Domain-PRO Web interface has a page for managing your CanIt Cluster. To access the
page, click on Setup and then Cluster Management. The Cluster Management page appears:
Figure 5.8: Cluster Management Page
The various machines in your cluster are shown. Each member of a CanIt-Domain-PRO cluster can
run one or more services. The services are:
• Scanner – this service scans mail flowing through the cluster member. Typically, all members
of a CanIt-Domain-PRO cluster will run this service, although large installations may not run a
scanner on the database host. NOTE: All nodes should be marked “Scanner” even if they don’t
actually act as MX hosts. This is to permit locally-generated traffic such as cron messages to be
delivered. Do not turn off the “Scanner” service on any cluster members. If you think you need
to, please contact Roaring Penguin support first.
• Ticker – this service runs periodic maintenance jobs. Exactly one host in the cluster must run
this service. That host must also run the Scanner service.
• Main Database – this service is the main PostgreSQL database. One host in the cluster must
be an active database server, but it is possible to set up a failover database server.
• Web Server – this service provides the Web interface and REST-based API. it can run on as
many hosts as you like.
• Inbound – this host processes inbound email. Always leave this setting enabled; if you think
you need to disable it, please contact Roaring Penguin technical support. Note that the ticker
must be marked as an Inbound scanner.
If a host is not marked as inbound, then:
1. Verification Server checks are skipped.
2. (Appliance Only) Domain Routing entries are ignored by the host (mail is routed solely
according to MX records) and Sendmail access entries are not created for domains in the
Domain Routing table.
• Outbound – this host processes outbound email. Always leave this setting enabled; if you think
you need to disable it, please contact Roaring Penguin technical support.
If a host is not marked as outbound, then:
1. The “Allow Relaying” Known Networks flag is ignored.
64
2. The “Force to Stream” Known Networks entry is ignored.
• Sync Bayes – this host requires Bayes data for processing email. Always leave this setting
enabled; if you think you need to disable it, please contact Roaring Penguin technical support.
• Log Host – this host contains mail logs that should be indexed for the Log Search Feature. Note
that this feature is available only on Hosted CanIt and our CanIt appliances.
• Storage Manager – if you are using the Storage Manager, the table will indicate on which hosts
it is running. You can run Storage Manager on as many hosts as you like.
5.6.1
Bandwidth Optimization for Copying Files
CanIt-Domain-PRO copies files from the ticker to other cluster members on a regular basis. For
example, this is how Bayes databases are distributed. If every cluster member is given a non-blank
location, then CanIt-Domain-PRO can optimize the use of relatively slow links. Here is an example:
Suppose you have three data centres A, B and C. Suppose that within a data centre, cluster members
are connected by 1Gb/s Ethernet, but between data centres there is only a 10 Mb/s link. Furthermore,
suppose that you have three hosts in each data centre with the ticker host in A.
If you set the locations of the hosts to “A”, “B”, and “C” according to which data centre they are in,
then when CanIt-Domain-PRO copies files, it performs the following steps:
1. The ticker copies the files to all machines in its location (A) and to one machine into each of the
other locations. These other machines are called the representatives.
2. Then for each representative, CanIt-Domain-PRO copies the files from that machine to the other
machines that are in the same location as the representative.
You can use whatever labels you like for the Location field as long as machines that are in the same
location have the same label. Note also that every machine in the cluster must have a non-blank
location or CanIt-Domain-PRO will not perform bandwidth optimization.
5.6.2
Altering Services on a Cluster Member
To alter the services running on a cluster member:
1. Check or uncheck the appropriate checkbuttons or radio buttons in the Scanner, Ticker, etc.
columns. Note that that the Database and Web Server checkboxes are informational; changing
them won’t actually change which services run on the host. And the Storage Manager column
is read-only because storage manager hosts are configured in the Storage Manager Wizard.)
2. Click Submit.
5.7. KNOWN NETWORKS
5.6.3
65
Renaming of Cluster Members
If you rename a CanIt-Domain-PRO host, the cluster management software usually picks up on the
name change automatically. If, however, nonexistent or dead hosts appear in the Cluster Management
table, you can delete them. To delete hosts:
1. Enable the appropriate checkboxes in the Delete column.
2. Click Submit.
Internally, CanIt-Domain-PRO identifies hosts with a UUID, which is an identifier that looks something like this:
30829e66-4df8-11e2-95d2-e6dca73e5dae
The
UUID
of
a
given
CanIt-Domain-PRO
/etc/mail/canit/canit-cluster-member-id.
this command:
host
is
stored
in
the
file
You can find the UUID by running
# head -n 1 /etc/mail/canit/canit-cluster-member-id
In the Cluster Management screen, hovering over the host name reveals the UUID of the host. This
can help you to decide which to delete in case two identical host names appear.
5.7
Note:
Known Networks
CanIt-Domain-PRO allows you to enter a list of “known networks”. These are typically networks
that you control, and for which you wish to alter the normal CanIt-Domain-PRO processing flow.
For example, you may not wish to scan outgoing mail for spam; if all outgoing mail originates from a
known set of IP addresses, you can tell CanIt-Domain-PRO to skip spam-scanning for mail originating
from those IP addresses.
To edit the list of known networks, click on Setup and then Known Networks. The Known Networks
page appears:
Figure 5.9: Known Networks
Each network appears as a row in the table. By default, CanIt-Domain-PRO abbreviates the attribute
names to avoid a very wide page that requires horizontal scrolling. You can hover over the abbreviation
to see the full attribute name, or click Full Headings to show the full attribute names.
In the example in Figure 5.9:
66
• The host 192.168.10.6 will not be looked up in any RBL blacklists.
• Mail originating from 192.168.10.6 will not be scanned for spam:
• Mail originating from 192.168.10.6 cannot be blacklisted. That is, any sender, domain or host
blacklists will be ignored.
• Greylisting will be turned off for 192.168.10.6.
• 192.168.10.6 will never be banned by the Dictionary Attack Detector.
• Mail originating from 192.168.10.6 will be streamed into the Outgoing stream, no matter what.
To add a network to the list of known networks:
1. Enter the network address in the Network box. A network address can either be a single IP
address, or a network address in CIDR notation: a.b.c.d/bits. In this notation, a through
d are decimal numbers from 0 to 255, and bits is a number from 1 to 32 specifying how
many bits of the address are significant. Note that the remaining bits (32 – bits) must be
zero. (For more information on CIDR notation, please see http://en.wikipedia.org/
wiki/Classless_Inter-Domain_Routing.)
Here are examples of network addresses:
• 192.168.1.0/24 specifies the Class C network 192.168.1.0 through 192.168.1.255.
• 10.5.2.0/23 specifies the IP addresses 10.5.2.0 through 10.5.3.255.
• 192.168.5.5/24 is invalid, because the lower 8 bits of the address must be zero.
2. Choose the characteristics you wish to apply to hosts in the known network (you may need to
click on Full Headings to see the full names of each characteristic.)
• To skip DNS-based RBL lookups, enable Skip RBL Lookups (srl).
• To skip spam-scanning, enable Skip Spam Scan (sss).
• To skip virus-scanning, enable Skip Virus Scan (svs).
• To skip filename and filename extension checking, enable Skip Extension Rules (ser).
• To skip MIME-type checking, enable Skip MIME-Type Rules (smr).
• To skip enforcement by CanIt-Domain-PRO of maximum message size, enable Skip Size
Limit Checks (ssl).
• To prevent sender, domain or host blacklists from applying to mail sent from the network,
enable Prohibit Blacklisting (pb).
• To skip greylisting for hosts in the network, enable Skip Greylisting (sg).
• To skip SPF checks for hosts in the network, enable Skip SPF Checks (ssc). Note that
this also disables DKIM and DMARC checking.
• To disable delay rules for hosts in the network, enable Skip Delay Rules (sdr).
• To disable attachment-stripping rules for hosts in the network, enable Skip Attachment
Stripping (sas).
5.7. KNOWN NETWORKS
67
• To prevent any hosts in the network from being banned by the Dictionary Attack Detector
(Section 5.3.3), enable Omit from Dictionary Attack Detection (oda).
• If all hosts in the network are “friendly”, then enable Friendly Host (fh). If mail from
a friendly host must be rejected, then CanIt-Domain-PRO simply discards it rather than
replying with an SMTP 5xx code. This is used to prevent backscatter.
• To have CanIt-Domain-PRO parse Received: headers to find the sending relay, enable
Parse Received Headers (prh). CanIt-Domain-PRO parses through the headers until it
finds a host that isn’t in a known-network with this flag set. If CanIt-Domain-PRO parses
the Received: headers, then the host that directly initiated the SMTP connection to the
CanIt-Domain-PRO scanner is called the Connecting Relay whereas the host parsed out of
the Received: headers is called the Sending Relay. If CanIt-Domain-PRO does not parse
the Received: headers, then the Sending Relay and the Connecting Relay are one and the
same.
• To auto-whitelist recipients of messages from a known network, enable Auto-Whitelist
Recipients (awr). This means that for messages originating from the network, the recipients of the message are whitelisted in the Sender Rule table.
Note that auto-whitelisting is not applied if any of these conditions holds:
– There is already a sender rule for the recipient in the stream in which the Sender
Whitelist rule would normally be created.
– The message has a “Precedence: bulk” or “Precedence: junk” header.
– The message has an “Auto-Submitted” header, as specified in RFC 3834.
– The message is a bounce message (in other words, the sender is <>.
– The message subject contains “[no-whitelist]”. In this case, the [no-whitelist] tag is
removed before the message is delivered (so that the recipients do not see it.)
– The message subject matches the regular expression ˆout of.*office caseinsensitively.
– Auto-whitelisting has been disabled under Preferences : Quarantine Settings for
the sender’s stream.
Note that some auto-responder software ignores RFC 3834 and fails to add an “AutoSubmitted” header. This could lead to situations in which CanIt-Domain-PRO autowhitelists someone because of an auto-response. If you cannot convince your autoresponder software to add an Auto-Submitted header, you should complain to the vendor
of that software in an attempt to make it RFC-compliant.
If a stream inherits from a final stream, then the whitelist rule is created in the final stream.
Otherwise, it is created in the actual stream itself. Please see Section 10.3.1 on page 167
for the precise definition of a final stream.
• To allow outbound mail from the network to be relayed through the CanIt-Domain-PRO
machine, enable Allow Relaying (ar).
Note:
Outbound relaying can be enabled from the Web interface only on CanIt-Domain-PRO
appliances or Linux-based RPM builds with the appliance RPMs installed. Also, this flag
is ignored on nodes that are not marked “Outbound” in the Cluster Members Table.
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• To rate-limit how many recipients per hour a given sender can send to, enter a number in
Per-Sender Recipient Rate Limit. If you use this option, you must also enter a Force To
Stream value. Rate-limiting is described more fully in Section 5.8.
• If you wish to rate-limit by sending IP address as well as sending email address, enter the
appropriate limit in the Per-IP Recipient Rate Limit box. See Section 5.8.1 for details.
• To force all mail from the network to be streamed into a specific stream, enter the name
of the stream in the Force To Stream box. Note: You must supply a fully-qualified
stream name of the form realm:stream. If you use the magic value @@ as the
realm name, then the message is forced into the realm of the envelope sender and the
given stream. For example, if you set the Force To Stream value to @@:outgoing
and the domain example.com is mapped to the realm example-com, then mail
from [email protected] originating from the known network will be forced into the
stream outgoing in the realm example-com. Alternatively, you can use a forced-to
stream name of the form somerealm:@@. Continuing our example, that would force
mail from [email protected] originating from the known network into the stream
example-com in the realm somerealm.
Note that the Force To Stream box is ignored on nodes that are not marked “Outbound” in
the Cluster Members Table.
If mail is forced to a stream, CanIt-Domain-PRO does not perform any SPF, DKIM or
DMARC checks, since forcing mail to a stream typically indicates outbound mail.
3. Click Submit Changes to have your changes take effect.
To edit an existing known network, simply adjust the attributes as required and click Submit Changes.
To delete a known network, enable the Delete? checkbox and click Submit Changes.
5.7.1
Associating Domains with Known Networks
Each Known Network may be associated with any number of domains. To view the list of associated
domains for a given network, click on the “Show” button in the “Associate Domains” column. The
list of Associated Domains appears:
Figure 5.10: Known Network with Associated Domains
5.8. RATE-LIMITING OUTBOUND MAIL
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In this example, the domains example.com and example2.net are associated with the network
192.168.7.88. Additionally, email originating from that network is normally forced into the outbound stream, but if email originating from that network has an envelope sender whose domain is
example2.net, then it will be forced into the outbound-example2.net
To associate a domain with a network, simply enter the new domain name in the Domain box. You
may optionally specify a domain-specific Force To Stream value in the Force To Stream box; this
overrides the general Force To Stream setting associated with the network.
Click Submit Changes to add the domain. To remove domains from the list of associated domains,
enable the appropriate checkboxes in the Delete? column and click Submit Changes.
If you have enabled the Allow Relaying (ar) flag on a known network, the Relay Unlisted Domains
(rud) flag will normally be on as well. This tells CanIt-Domain-PRO to relay all mail from the
specified network, regardless of the sender domain. If, however, you turn off the Relay Unlisted
Domains (rud) flag, then CanIt-Domain-PRO will refuse to relay mail from the given network unless
the domain of the envelope sender is in the list of domains associated with the network. (CanItDomain-PRO always permits relaying of the null return path, <>.) We do not recommend turning off
Relay Unlisted Domains unless you are absolutely sure the network never originates or forwards mail
from a domain not in the list of associated domains.
5.7.2
Overlapping Networks
If you add two networks that overlap, CanIt-Domain-PRO will use the most-specific network
for a given host. That is, CanIt-Domain-PRO will choose the smallest network that contains a given host. For example, if you create the known networks 192.168.1.0/24 and
192.168.1.240/28, then hosts in the range 192.168.1.240 through 192.168.1.255
will use the 192.168.1.240/28 settings, whereas hosts from 192.168.1.0 through
192.168.1.239 will use the 192.168.1.0/24 settings.
Note:
Because of how Sendmail’s access map works, the handling of overlapping networks described above
does not apply to the Allow Relaying (ar) setting. Instead, relaying will be permitted for any host in a
network with the flag enabled even if there is a more-specific network with the flag turned off. If this
is of concern, then you need to split your Known Networks entries into non-overlapping networks.
5.7.3
The SMTP-AUTH Pseudo-Network
CanIt-Domain-PRO supports a pseudo-network called SMTP-AUTH. (It must be entered exactly like
that in upper-case.) Any Known Network settings for this network will be applied to users who
authenticate using SMTP AUTH. This lets you do things like force authenticated mail into a particular
stream or skip spam-scanning for authenticated users.
5.8
Note:
Rate-Limiting Outbound Mail
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The Known Networks feature allows you to limit the number of recipients a given sender can mail in
an hour. This can be useful to catch compromised internal hosts that are used to send spam. Here is
how rate-limiting works:
• Normally, you can only rate-limit mail from a Known Network. This is because rate-limiting is
designed to rate-limit outbound mail from a set of machines under your control. Under special
circumstances, you can enable rate-limiting for any stream other than default, but you should
normally not use rate-limting for inbound email.
• To specify a rate limit, enter the maximum number of recipients per hour that a given sender can
send to. A reasonable value might be 500 to 1000; a value of 0 disables rate-limiting completely.
(Enter the value in the Recipient Rate Limit column of Known Networks.)
• The rate limit may be positive or negative. CanIt-Domain-PRO treats limits as follows:
– If the limit is positive, then a sender who exceeds the limit is permanently blocked. Any
mail from that sender is rejected with an SMTP permanent-failure code.
– If the limit is negative, then a sender who exceeds the absolute value of the limit is tempfailed. Any mail from that sender is rejected with an SMTP temporary-failure code.
• You must also specify a Force To Stream value in order to use rate-limiting.
If a sender exceeds the rate limit, CanIt-Domain-PRO creates a Sender rule in the Force To Stream
stream. The rule rejects all mail from the sender. This has the effect of completely disabling all
outbound mail from the sender address. The sender rule that CanIt-Domain-PRO creates is set to
expire automatically three days after it is created.
CanIt-Domain-PRO also sends an email to the CanIt-Domain-PRO administrator informing him or
her of the rule that blocks the sender. Note that the sender will be unable to send outbound mail until
the administrator goes into the Force To Stream stream and manually removes the rule that blocks
the sender (or until the rule expires after three days.)
Note:
Any sender that has any Sender Rule defined in the outbound stream will not be subject to ratelimiting. You can use this as an “escape hatch” to permit certain senders to send high volumes of
mail; simply whitelist those senders in the forced-to stream (or add a “Hold if looks like spam” rule
for those senders.) However, you should be very careful to do this only for legitimate senders who are
unlikely to have their accounts hijacked. Also, note that if a sender is whitelisted for any reason (ie, a
sender whitelist, domain whitelist or host whitelist), rate-limiting will not apply. For this reason, you
should be very judicous about the whitelists you create in the forced-to stream and consider setting up
the forced-to stream not to inherit from the default stream.
Note:
If you enable rate-limiting on a Known Network, be sure that you do not enable the “Prohibit Blacklisting” option for that network. Otherwise, rate-limiting rules will be ignored! In addition, if you
rate-limit the SMTP-AUTH pseudo-network, be sure not to enable the global setting “Whitelist users
who use SMTP authentication” (G-3600) or rate-limiting will be ignored.
5.8.1
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Rate-Limiting by IP Address
Normally, CanIt-Domain-PRO applies rate-limiting on a per-sender email address basis. If you enable
the Per-IP Recipient Rate Limit feature in Known Networks, CanIt-Domain-PRO will also apply
rate-limiting to the sending IP address. If the Known Networks entry has Parse Received Headers
enabled, then the IP address that is rate-limited is extracted from the Received: headers.
As with the sender rate-limit, the IP-based rate limit may be positive or negative, with positive limits
yielding an SMTP permanent-failure code and negative ones yielding a temporary-failure code if the
limit is exceeded.
Note:
Be very careful when enabling IP-based rate-limiting. If all of your mail goes out through one server
and you accidentally turn on rate-limiting by IP address without enabling Received: header parsing,
you may end up blocking all outbound mail. The rule of thumb is as follows:
• If various clients connect directly to the CanIt-Domain-PRO server to send outbound email,
you must not enable Parse Received Headers on the Known Network containing the client IP
addresses.
• If clients relay via an SMTP server that subsequently relays out via the CanIt-Domain-PRO
server, then you must enable Parse Received Headers.
5.8.2
Note:
Fine-Grained Rate-Limiting Rules
By default, realm administrators do not have permission to create rate-limiting rules, but permission
can be granted by the CanIt-Domain-PRO site administrator.
In addition to per-known-network rate-limits, you can create finer-grained rate-limiting rules by clicking Rules : Rate Limiting. The Rate-Limiting Rules page appears (Figure 5.11):
Figure 5.11: Rate-Limiting Rules
Normally, CanIt-Domain-PRO only applies rate-limiting rules for a stream if the mail has been forced
into that stream by a Known Networks match. However, for streams other than default you can
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change the setting “Apply rate-limiting rules in stream?” to Always to always apply the fine-grained
rate-limiting rules, even if mail was not forced into the stream by a Known Networks match. We
do not recommend applying rate-limiting to inbound streams; you should normally never change this
setting.
Rate-limiting rules permit you to use one of the following in the Originator column:
For sending email addresses:
• A full email address, which applies to a specific sender.
• A domain name, which applies to all senders in that domain. Note that a full email address rule
will override a domain rule.
• A single asterisk, which applies to senders that don’t have a full email address or a domain name
match.
For sending domains:
• A domain name prefixed by ‘@’ which limits mail from all senders within that domain.
• The value @* which applies to all domains.
The difference between a sending email address limit and a domain limit is that domain limits apply
cumulatively to any email address within the domain. Thus, a limit of 100 recipients per hour for
example.com limits any given sender within the “example.com” domain to 100 recipients per hour.
On the other hand, a limit of 100 recipients per hour for @example.com limits the total number of
recipients for all addresses within the “example.com” domain to 100 recipients per hour.
For sending machines:
• An IPv4 or IPv6 address, which applies IP-based rate-limiting to a specific IP address.
• The IP address 0.0.0.0, which applies IP-based rate-limiting to machines that don’t have a specific IP address rule. (This includes IPv6 machines.)
In the example in Figure 5.11, the following sender rate limits apply:
• The sender “[email protected]” is limited to 100 recipients per hour.
• The sender “[email protected]” is limited to 500 recipients per hour.
• The sender “[email protected]” has no rate-limits set.
• All senders in the “example.com” domain are limited to 200 recipients per hour.
• All other senders are limited to 150 recipients per hour by the “*” entry.
The following domain-based rate limits apply:
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• Senders in the domain “example.net” are cumulatively limited to 300 recipients per hour.
• Senders in all other domains are cumulatively limited to 200 recipients per hour.
And finally, the following IP-based rate-limits apply:
• The machine 10.2.3.4 is allowed to send to 10000 recipients per hour.
• All other machines are limited to 500 recipients per hour by the “0.0.0.0” entry.
To create a rate-limiting rule:
1. Enter the sender address, domain name, IP address, “*” or “0.0.0.0” in the Originator box.
2. Enter a number from 0 to 100000 in the Hourly Limit box. An entry of 0 means that no
rate-limiting is to be applied. Any other entry N applies a rate-limit of N recipients per hour.
3. Select an action from the Action pull-down. Available actions are:
• Reject — if the rate-limit is exceeded, CanIt-Domain-PRO creates a rule that blocks the
sender or IP address. Mail from the blocked originator will simply be rejected.
• Tempfail — if the rate-limit is exceeded, CanIt-Domain-PRO creates a rule that always
tempfails the originator. This permits administrators to examine the situation and unblock
the originator if necessary.
• Hold Always — if the rate-limit is exceeded, CanIt-Domain-PRO quarantines all mail
from the originator. Again, this permits administrators to examine the situation and release
the quarantined messages if they are legitimate.
4. Enter a number from 1 to 30 in the Block Duration field. When CanIt-Domain-PRO creates a
Reject, Tempfail or Hold Always rule, it sets it up to expire after N days, where N is the number
you enter for Block Duration.
5. If you wish, enter a comment in the Comment box to help remind you why you made the rule.
6. Click Submit Changes
To delete rate-limiting rules, enable the appropriate checkbox in the Delete? column and click Submit
Changs.
5.8.3
Notes about Rate-Limiting Rules
• Rate-limiting rules are applied only for mail that is forced into a stream by a Known Networks
entry. Normal inbound mail is never rate-limited.
• Rate-limit settings are inherited across streams. CanIt-Domain-PRO uses the best match in the
most-specific stream to determine the rate-limit. For example, suppose the stream outbound
inherits from the stream default. Suppose that outbound has a rule for “example.com” and that
default has rules for “[email protected]” and “*”. Then:
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1. An originator “[email protected]” will use the “example.com” entry from outbound.
That’s because outbound is more specific than default and it did have an entry that
matched the originator.
2. An originator “[email protected]” will use the “*” entry from default because no rule in
outbound matched.
• When a rate-limit is hit and a rule is created, the rule is always created in the forced-to stream
from the Known Networks entry. Additionally, CanIt-Domain-PRO sends an email to the site
administrator informing him or her that the originator has exceeded the rate limit.
• If you use a Hold Always rule, make sure the forced-to stream is not a tag-only stream. Otherwise, mail from the originator will be tagged rather than quarantined.
• Make sure the forced-to stream is not opted-out of spam-scanning or any hold, tempfail or reject
rules will be ignored.
• If an originator does not match any rate-limiting rules, then the rate limits from the Known
Network entry (if any) apply.
• The “Hourly Limit” refers to the total number of recipients mailed, not the number of unique
recipients. For example, if a given sender sends 50 copies of a message all to the same recipient,
that counts as 50 recipients, not one recipient.
5.9
Note:
Features
The Features page allows you to globally disable certain CanIt-Domain-PRO features to reduce the
number of database queries. Note that disabling a feature completely disables it system-wide. Unless
you know for sure that you don’t need a feature, and you know that the load savings will be worth
turning it off, you should leave all features in their default states.
To disable a set of features, click on No in the Enabled column for the features you want to disable.
Then click Submit Changes.
Some features are disabled by default because they are considered dangerous or are only useful in
special situations. You can enable such features by selecting Yes in the Enabled column and then
clicking Submit Changes.
5.9.1
Direct Queue Injection
Normally, when CanIt-Domain-PRO needs to split an incoming message destined for several streams
into several single-stream messages, it performs the following actions:
1. It remails a copy of the message for each stream by invoking sendmail with appropriate
arguments.
2. It discards the original message.
5.10. SYSTEM CHECK
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Remailing a message with Sendmail is expensive because multiple copies of the message data are
made and Sendmail uses expensive disk synchronization operations after each copy.
CanIt-Domain-PRO can instead directly inject copies of the streamed messages into Sendmail’s local
client queue. This saves disk I/O because only one expensive synchronization operation is needed (not
one per copy.) Also, the data can be hard-linked instead of copied, saving disk space.
In order for this to work, the defang user must be a member of the smmsp group. (This is the case
if you are running an appliace or an RPM build.) Additionally, you must enable the “Insert Streamed
Mail Directly Into Sendmail Queue” feature under Setup : Features.
5.10
System Check
The System Check page runs some sanity checks on your CanIt-Domain-PRO installation. It also
displays the current versions of RPTN data and Roaring Penguin rule sets. A typical System Check
page is shown in Figure 5.12:
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Figure 5.12: System Check
In addition to running a few local tests, viewing the System Check page also shows the results of
cluster-wide tests performed on a periodic basis. If System Check indicates a problem, you should
take action to fix it immediately. The various System Check tests are outlined in Appendix L.
5.11
Templates
CanIt-Domain-PRO uses templates to configure how Bayes training information is added to messages
and to configure the appearance of Pending Message Notifications. These templates may be configured
on a per-realm basis.
To configure templates, click on Setup and then Templates. The Templates screen appears:
5.11. TEMPLATES
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Figure 5.13: Templates
The various templates you can configure are:
• Base URL of CanIt installation is used to construct URLs in messages sent out by CanItDomain-PRO.
• Base URL for URL-Rewriting is used to construct URLs when rewriting URLs (Chapter 14).
Normally, you should leave this template blank, in which case the Base URL of CanIt installation is used.
• E-Mail address of CanIt System Administrator is the e-mail address to which CanIt-DomainPRO sends certain warning messages or alerts.
• Source E-Mail address of CanIt notifications is the sender address used by CanIt-DomainPRO when it e-mails notifications. This is the envelope sender address.
• Full name for sender of CanIt notifications is the full name placed in the From: header of
CanIt-Domain-PRO notifications.
• Header From: address of sender of CanIt notifications is the email address placed in the
From: header of CanIt-Domain-PRO notifications. If this template is left blank, then CanItDomain-PRO uses the value from “Source E-Mail address of CanIt notifications”.
• SMTP reply for a rejected incident is the text returned with the SMTP permanent failure code
when CanIt-Domain-PRO rejects an incident.
• SMTP reply for a blacklist entry is the text returned with the SMTP permanent failure code
when CanIt-Domain-PRO rejects a host, sender or domain that is blacklisted.
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• Header note for a whitelist entry is the note CanIt-Domain-PRO places in the X-Spam-Score
header when a host, sender or domain is whitelisted.
• Plain-text training link body specifies the appearance of Bayesian training links added to
plain-text messages.
• HTML training link body specifies the appearance of Bayesian training links added to HTML
messages.
• Pending notification e-mail subject specifies the subject to put in Pending Notification messages.
• Pending notification e-mail body specifies the body of Pending Notification messages
• Preamble before notification details specifies the preamble before the detailed list of held
messages (for users who select verbose notifications.)
• Detailed pending notification entry specifies the format for each held message in detailed
notifications.
• Subject for Add Alternate Address e-mail specifies the subject of the confirmation e-mail
sent when someone attempts to add an Alternate Address to his/her stream.
• Body for Add Alternate Address e-mail is the body of the confirmation e-mail described
above.
• Header for ’Webform’-style Pending Notification is the HTML preamble used for “Webform” pending notifications.
• Footer for ’Webform’-style Pending Notification is the HTML postamble used for “Webform” pending notifications.
• Subject line for Periodic Reports is the subject used by CanIt-Domain-PRO when mailing out
periodic reports.
• Body of Periodic Report e-mail is the body used by CanIt-Domain-PRO when mailing out
periodic reports. It should consist of valid HTML.
• Text boilerplate when attachments are stripped is appended to the first text/plain email
part if an attachment is stripped and stored on the CanIt-Domain-PRO server.
• HTML boilerplate when attachments are stripped is appended to the first text/html
email part if an attachment is stripped and stored on the CanIt-Domain-PRO server.
• Text boilerplate when attachments are discarded is appended to the first text/plain
email part if an attachment is stripped and discarded.
• HTML boilerplate when attachments are discarded is appended to the first text/html
email part if an attachment is stripped and discarded.
• Forgot-your-Password Link or Text is the link or text used for the Forgot your Password?
message on the login page.
5.12. THEME CUSTOMIZATION AND BRANDING
79
• HTML content for anti-phishing URL Redirection page is the content of the URL Proxy
warning messag. See Chapter 14, “URL Proxying”, for details on the URL Proxying feature.
• HTML content for anti-phishing URL Redirection page encountering a Phishing URL is
the content of the URL Proxy message when a suspected phishing link is encountered. See
Chapter 14, “URL Proxying”, for details on the URL Proxying feature.
Note that many templates include various “replacement tags”. For example, in the training link templates, the sequence of characters %spamurl or %{spamurl} will be replaced with a URL that
votes the message as spam. To see the list of available replacement tags, click on the “(Tags)” link
near the template entry box.
If you change the value of a template in a non-base realm, you can revert to the previous value by
clicking the “(Revert to Original)” link next to the template name.
5.12
Theme Customization and Branding
CanIt-Domain-PRO ships with several themes which control the “look and feel” of the Web interface.
Some of those themes can be customized. That is, although the basic layout of the theme cannot be
changed via the web interface, the colors of various elements can be and (in some cases) the logo can
be changed as well. This permits you to “brand” CanIt-Domain-PRO with your corporate logo.
To customize a theme, click on Setup : Theme Customization. The Theme Customizations page
appears:
Figure 5.14: Theme Customizations
Note:
The list of available customizations is specific to the current theme and realm. If you switch themes
or realms, then the list of available customizations will change. Also, some elements such as images
on the login page may only be cusomizable in the base realm and therefore can be customized only
by the site administrator.
To activate a customization, enable the corresponding Active radio button and click Submit Changes.
That customization will become active for the current theme and realm. It will also be active for all
subrealms unless overridden within a subrealm.
To deactivate all customizations, click Deactivate All. This will revert the current theme and realm
including subrealms to the default un-customized appearance.
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To delete a customization, enable the corresponding Delete? checkbox and click Submit Changes.
5.12.1
Creating or Editing a Customization
To add a new customization, click Add New Customization. To edit an existing customization, click
on the name of the customization you wish to edit. In either case, the Theme Customization Editor
appears:
Figure 5.15: Theme Customization Editor
The Theme Customization Editor lets you alter the appearance of various components of the web
page. To edit a customization:
1. If you are adding a new customization, the Customization Name field will be blank. Enter the
name of your new customization. Note that customization names must be unique for a given
theme and realm.
2. To change image items, upload a GIF, JPEG or PNG file from your computer.
3. To change color items, enter a “#” followed by an HTML color triplet in the text box. If you
click on the color swatch to the right of the text box, you can pick a color from a color selector.
4. Some themes may allow you to enter arbitrary CSS information. This lets you have very fine
control over the appearance of the theme, but you should not make use of this facility unless you
are very familiar with HTML and CSS.
5. If you want to revert a particular item to its theme default, enable the Revert to default? checkbox.
6. Click Save to save your customization and continue editing it. Or click Save and return to list
to save your customization and return to the list of available customizations.
Note that while you are editing a customization, it becomes active so you can see in real-time what
the customized theme looks like. Other users, however, will not see the customized theme until you
activate it from the list of customizations.
5.13. HTTPS
5.12.2
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Emergency Recovery from Bad Theme Customization
If you make a mistake while creating a theme customization and end up with web pages you can’t
read or navigate, follow these emergency instructions:
• Look at the URL in the URL bar of your browser. If it contains a question-mark, add the
following text on the end of the URL:
&disable theme customization=1
If it does not contain a question mark, add this at the end:
?disable theme customization=1
• Press Enter to visit the newly-edited URL
• Navigate back to Setup : Theme Customization and fix the problem. Note that you have to
adjust the URL in the URL bar each time you navigate to a new page, so you might need to do
it a few times until the problem is fixed.
5.13
Note:
HTTPS
This feature is available only on Debian-based Appliances.
On CanIt-Domain-PRO appliances, HTTPS is enabled by default, but with dummy self-signed certificates. If you would like to install your own certificates, click on Setup : HTTPS. Then:
1. Copy-and-paste your SSL certificate into the first text box. If your certificate provider requires
you to install an intermediate certificate chain, paste the entire contents of the certificate chain
file into the first text box immediately after you paste in your SSL certificate.
2. Copy-and-paste the corresponding server key into the second text box. The server key must not
be encrypted or the Web server on the appliance will fail to start.
3. Click Submit Changes to install the key and certificate.
5.14
The Domain Mapping Table
Recall from Figure 2.4 on page 35 that CanIt-Domain-PRO uses a Domain Mapping Table to determine how to stream messages for each domain. The table contains a list of domains with a corresponding lookup method. To edit the Domain Mapping Table, click on Setup and then Domain Mappings.
The Domain Mappings page appears:
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Figure 5.16: Domain Mappings
To add a mapping method for a particular domain, enter the domain name in the top row of the table
and select a value in the Mapping column. The possible choices are:
• Database—CanIt-Domain-PRO will look up a stream mapping in the Address Mapping Table
(Section 5.15).
• AsIs—CanIt-Domain-PRO converts an address to a stream by removing any angle-brackets and
converting letters to lower-case.
• ChopDomain—CanIt-Domain-PRO converts an address to a stream simply by chopping off the
@domain.tld part, removing any angle-brackets, and converting to lower-case.
• ChopUser—CanIt-Domain-PRO converts an address to a stream simply by chopping off the
address@ part, leaving just the domain (without angle-brackets and converted to lower-case.)
• Program—CanIt-Domain-PRO converts an address to a stream by executing the
account-info program. Please see Section 7.2.4 on page 149 for more details. Note that
Program is deprecated; you should create and use a User Lookup method instead.
• None—CanIt-Domain-PRO removes the domain from the Domain Mapping Table.
• If you have added external User Lookup methods (Chapter 7), some of them may appear as
additional choices. For example, the LDAP, Rewrite and Program User Lookup methods can
convert an address to a stream. If there are any User Lookup methods added to ancestor realms
of the current realm, they will appear as additional choices if they are marked as being available
for subrealms.
Click Submit Changes to save your changes.
To modify the mapping for an existing domain, select a new mapping in the Mapping column and
click Submit Changes.
5.15. THE ADDRESS MAPPING TABLE
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Given a domain sub.example.com, CanIt-Domain-PRO looks up entries in the Domain Mapping
Table in the following order, stopping at the first one found:
1. sub.example.com
2. example.com
3. com
4. *
The special domain * is used as a last resort if no better match is found. You may enter a mapping for
* to set a default mapping. If there is no * entry and a domain is not found in the Domain Mapping
Table, then CanIt-Domain-PRO uses a default lookup method of Database.
Domain or Mapping columns contain that string.
5.15
The Address Mapping Table
CanIt-Domain-PRO uses an Address Mapping Table (Figure 2.4 on page 35) to map e-mail addresses
to streams. The Address Mapping Table is used both for hand-entered entries placed there by the
CanIt-Domain-PRO administrator, and for caching the results of the Program mapping method.
Note:
If there is an exact match for an email address in the Address Mapping Table, then it is always used,
overriding any mapping method.
To edit the address mapping table, click on Setup and then Address Mappings. The Address Mappings page will appear:
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Figure 5.17: Address Mappings
To add an entry for a new e-mail address, enter the new address in the Address column of the first
row, and enter the stream name in the Mapping column. Then click Submit Changes.
To edit an existing entry, edit the text in the Mapping column and click Submit Changes. To delete
an entry from the table, click the Delete link in the appropriate row.
Click on Not Cached to see only non-cached (hand-entered) entries, Cached to see only cached
entries, or Any to see all entries in the Address Mapping Table.
Address or Mapping columns contain that string.
5.15.1
Wild-Card Entries
The address mapping table may contain three types of wildcard entries:
1. The entry user@* is used if CanIt-Domain-PRO is unable to map an address to a stream with
an exact match. If you run several domains, but all user-parts are the same, this wildcard can be
useful.
2. The entry *@domain.tld is used if the previous wildcard does not match anything. Use this
entry to set up a default stream for e-mail to a particular domain.
3. The entry * is used as a last resort if the previous wildcards did not match.
Note:
The addresses postmaster, postmaster@localhost and postmaster@machine name
are always mapped to the default stream unless you have a specific entry in the Address Mapping
5.16. THE DEFAULT STREAM
85
Table for those addresses. That is, for those three specific addresses, CanIt-Domain-PRO will not use
wildcard matches or User Lookups to determine the stream. (In the third address, machine name is
the name of the host processing the email.)
5.16
The default Stream
CanIt-Domain-PRO has a built-in stream name that is reserved, and which cannot be used for other
purposes. This stream is named default, and is used as follows:
If CanIt-Domain-PRO is unable to map an address to a stream (for example, if there are no exact or
wildcard matches in the database and the Program method fails), the address is mapped to the hardcoded stream default. The CanIt-Domain-PRO administrator should check the default stream
from time to time.
The default stream also contains whitelists, blacklists, and custom rules that all other streams can
inherit. The factory default is for all streams to inherit the lists and rules from default, but you
can disable this if you wish. List and rule inheritance work as follows for streams that inherit from
default:
• Senders, hosts, domains, extension rules and MIME type rules and are first looked up in the
stream’s table. If no entry is found, they are looked up in default’s table.
• Custom rules are evaluated first for the given stream, and then for default. Their scores are
added together. Note that if the same rule appears in both the stream’s rule set and default’s
rule set, it is counted twice.
5.17
Mapping Scenarios
To give a feel for how to use the mapping, we illustrate a few common scenarios.
5.17.1
Central Scanning with Opt-Out
If you run a mail server and wish to centralize spam-scanning, but you have some users who wish to
opt out or handle their own spam, you can do it as follows:
In the Address Mapping Table, add this catch-all entry:
Address Stream
admin
*
This streams most users’ e-mail to the “admin” stream for centralized processing. If user
[email protected] does not want his mail examined by the spam control officer, simply add
another entry:
Address
[email protected]
Stream
joe
This streams mail for [email protected] to joe.
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5.17.2
Single Domain
If you host a single e-mail domain, and each user’s login name is simply the first part of his/her e-mail
address, setting up mappings is easy. In the Domain Mapping Table, add a single entry:
Domain
*
5.17.3
Mapping Method
ChopDomain
Single Domain with Aliases and Mailing Lists
Most likely, your scenario is more complex than in Section 5.17.2. You probably host mailing lists,
and have aliases. Let’s suppose you host a list called [email protected], which is run by
jane, and that your [email protected] is an alias which gets expanded to jim and bob.
You can still use the same Domain Mapping as Section 5.17.2. You have two options for handling the
mailing list and sales alias:
1. Allow jane to access the tv-list stream, and allow jim and bob (or delegate one of them)
to access the sales stream. Jane will have to remember to check the tv-list quarantine as
well as her own quarantine, and similarly for Bob and Jim.
2. Add address mappings like this:
Address
[email protected]
[email protected]
Stream
jane
bob
Explicit entries in the Address Mapping Table will override even the ChopDomain method.
Here, Jane’s quarantine will contain messages both for herself directly and the mailing list she
runs. Bob’s quarantine will contain his messages and messages for sales. (Clearly, you’ve
delegated spam handling for sales to Bob alone.)
(You can, of course, use Method 1 for tv-list and Method 2 for sales. It’s up to you.)
5.18
Note:
Pausing Delivery to Selected Domains
This section is applicable only to CanIt appliances or the Hosted CanIt service.
CanIt-Domain-PRO permits you to temporarily pause delivery to selected domains. When delivery
to a domain is paused, CanIt-Domain-PRO will continue to accept mail for that domain, but will not
attempt to deliver it to the back-end server. Instead, it will simply queue the mail. When delivery is
resumed, the mail will be delivered out of the queue.
5.18.1
Pausing Delivery
To pause delivery to a domain:
1. Click on Setup and then Paused Delivery.
5.19. THE DOMAIN OVERVIEW PAGE
87
2. Enter the domain whose delivery should be paused in the Domain box.
3. Select a Pause Mode. The choices are:
• Delivery and LDAP/Verification: In this mode, CanIt-Domain-PRO will not attempt to
connect to any LDAP servers or verification servers. It will accept mail for addresses that
are in its cache and will tempfail mail for addresses that have not been verified or found in
the LDAP directory recently.
• Delivery Only: In this mode, CanIt-Domain-PRO will not attempt to deliver mail, but will
still connect to LDAP servers and verification servers as usual.
4. Enter the expiry time in the Expiry (Minutes) box. The site administrator may specify up to
one day (1440 minutes) and realm administrators may specify up to four hours (240 minutes).
5.18.2
Resuming Delivery
To resume delivery to a domain:
1. Click on Setup and then Paused Delivery.
2. Enable the Delete? checkbox for the domain whose delivery should be resumed.
5.19
The Domain Overview Page
For convenience, CanIt-Domain-PRO allows you to view the most important settings for your domains
in one place. To see the overview, click on Setup and then Domain Overview. If you have more than
one domain mapped to your realm, click on the domain name whose overview you desire. The Domain
Overview Page appears:
Figure 5.18: Domain Overview Page
The Domain Overview page shows some or all of the following information:
• The Verification Server settings for the domain. Click Edit to modify the settings.
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• The Domain Routing settings for the domain. Again, click Edit to adjust the settings.
• The Domain Mapping and Authentication Mapping settings for the domain. If the domain uses
a User Lookup for mapping or authenticaiton, you can click on the link in the Value column to
see the specific user lookup settings.
• Whether or not the domain correctly validates recipients (as checked by the last nightly cron
job.)
• Whether or not the domain’s MX records point at the CanIt-Domain-PRO filter (as checked by
the last nightly cron job.)
5.20
Note:
Autotask® Integration
Autotask integration is available only on Hosted CanIt and our Debian-based CanIt-Domain-PRO
appliances. It is not available in the source or RPM versions of CanIt-Domain-PRO.
Autotask® is a Professional Services Automation package designed for IT consultants and managed
service providers. CanIt-Domain-PRO can interface with Autotask to automatically generate billing
information so you can invoice your clients on a monthly basis.
The basic workflow for Autotask integration is as follows:
• Within Autotask, set up a product corresponding to CanIt-Domain-PRO services.
• For each customer, set up a realm within CanIt-Domain-PRO and an account within Autotask.
• For each customer, set up a monthly billing contract within Autotask
• Provide enough information to CanIt-Domain-PRO that it can push usage statistics to Autotask.
CanIt-Domain-PRO generates or updates a Contract Cost item, thereby permitting automatic
invoice generation.
Once Autotask integration is configured, CanIt-Domain-PRO will automatically post Contact Costs to
Autotask with a Unit Quantity corresponding to the number of mailboxes. The Contract Costs will be
update every day; this means that whatever your billing cycle is, Autotask will always have up-to-date
usage statistics.
5.20.1
Preparing Autotask
To prepare Autotask for CanIt-Domain-PRO integration, perform the following steps within your
Autotask account:
Create a Product corresponding to each CanIt-Domain-PRO service
Under Admin : Features & Settings : Products & Services, create a Product for each CanIt-DomainPRO service that you offer. Once you have finished, the results will look like Figure 5.19:
5.20. AUTOTASK® INTEGRATION
89
Figure 5.19: Autotask Product List
The possible products are:
• Inbound Scanning. In this example, we called the product CanIt-Inbound.
• Outbound Scanning. In this example, we called the product CanIt-Outbound.
• Secure Messaging. In this example, we called the product CanIt-SecureMessaging.
• Archiving. You should create one product for each possible retention time in months that
you sell. All of these products must have the same prefix, followed by -n where n is the
retention time in months. In Figure 5.19, we created three products with the common prefix
CanIt-Archiving and retention times of 1, 12 and 24 months.
Create a Recurring Service Contract within Autotask for each CanIt-Domain-PRO customer
Under Contracts, create a Recurring Service Contract for each CanIt-Domain-PRO customer. Figure 5.20 shows a sample contract, which we have named Email Security:
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Figure 5.20: Autotask Recurring Service Contract
5.20.2
Preparing CanIt-Domain-PRO
To prepare CanIt-Domain-PRO for Autotask integration, log in to your top-level realm (the “base”
realm if you are running CanIt-Domain-PRO on-premises or your realm if you are using Hosted CanIt.
Click on Setup : Autotask Integration. The Autotask settings screen appears:
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Figure 5.21: Autotask Integration Settings
Basic Information
Fill in the basic information needed to integrate with the Autotask API. Note that all settings follow
realm inheritance; you can override them as necessary on a per-realm basis. The basic settings are:
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• Autotask proxy URL: The URL for accessing the Autotask API. The default value is probably
fine and should not normally need to be changed.
• Autotask API username: A username with permission to access the Autotask API.
• Autotask API password: The password for the API user.
• Account name associated with current realm: The name of the account within Autotask. This
setting links the current realm in CanIt-Domain-PRO to the account in Autotask.
• Contract name associated with email security product: The Autotask contract name corresponding to the CanIt-Domain-PRO services.
• Billing metric: One of Addresses or Streams, depending on whether you bill on the basis of
number of email addresses or number of streams.
• Bill for subrealms as well as current realm: If set to Yes, then statistics for the current realm
and all of its descendants are counted for billing purposes. If set to No, then only statistics
within the current realm are pushed to Autotask.
Per-Product Settings
CanIt-Domain-PRO lets you push billing data for up to four product categories to Autotask. The four
categories are shown below. Note that you may not offer all categories to all of your clients.
1. Inbound Filtering: Inbound email filtering.
2. Outbound Filtering: Outbound email filtering.
3. Secure Messaging: Secure Messaging Service
4. Archiving: Email archiving.
To link each product to Autotask, fill in the following settings:
• Product name: The name of the corresponding product within Autotask. Note: Archiving is
a special case because CanIt-Domain-PRO always appends -n where n is the retention time
in months. Therefore, in the Archiving Settings section, the Product name setting specifies the
prefix to use.
• Unit cost: The unit cost of the product. For most products, this is simply a decimal number.
For Archiving, it is a string of the form:
n1=c1,n2=c2,...
which specifies that the cost for n1 months of retention is c1, for n2 is c2 and so on. You should
enter all combinations of retention time that are actually used by your clients. For example, in
Figure 5.21, the Unit cost of 1=0.5,12=1,24=2 means that one month of archiving costs
$0.50; 12 months costs $1.00 and 24 months costs $2.00
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• Unit cost: The unit price of the product. For most products, this is simply a decimal number.
For Archiving, it follows the same format as Unit price.
• Minimum number of units to bill: The minimum number of units to bill each month, if any.
For most products, this is an integer, but for Archiving, it follows the same format as Unit price
except only integers can appear to the right of each equals sign.
• Contract cost description: If non-blank, the description to use in the contract cost line item. If
this is left blank, the description is copied from the Autotask Product.
Once you’ve entered the values for your top-level realm, switch into each customer realm and set
(minimally) the Account name associated with the current realm as well as any other settings that
should be overridden.
5.20.3
Testing the Autotask Integration Settings
You can test the Autotask settings by enabling the Run a live test of these settings against Autotask
checkbox and clicking Submit Changes. CanIt-Domain-PRO will print a debug log and let you know
whether or not the settings look correct. Note that because fetching actual statistics is costly, the
debugging output always pretends to post random unit counts to Autotask. In production, the correct
number of addresses or streams would be posted to Autotask.
If you enable the Push a dummy ContractCost item to Autotask checkbox, then in addition to
running the tests, CanIt-Domain-PRO will push a ContractCost item up to Autotask
A successful debugging log is shown in Figure 5.22.
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Figure 5.22: Autotask Test Results
5.21. CONNECTWISE® INTEGRATION
95
Sample Contract Costs as they appear in Autotask after CanIt has pushed statistics are shown in
Figure 5.23.
Figure 5.23: Autotask Contract Costs
5.20.4
Autotask Settings and Inheritance
In the Autotask Integration Settings screen, the “Origin Realm” column shows the realm in which a
setting has been created. If the setting exists in the current realm, you can check the Reset? checkbox
to remove the setting and make the setting once again inherit the value from the parent realm.
Any realm that does not have an Autotask account name associated with it will not have its statistics
pushed to Autotask.
Note:
The first time CanIt-Domain-PRO connects to Autotask, it extracts the Account, Contract and Product
IDs from Autotask and from then on uses the Autotask IDs rather than the names to link to Autotask.
This allows you to rename objects within Autotask without breaking the CanIt-Domain-PRO integration. As a convenience, if CanIt-Domain-PRO notices that an object has been renamed in Autotask, it
updates its copy of the corresponding name to match Autotask’s.
5.21
ConnectWise® Integration
CanIt-Domain-PRO can automatically update mailbox counts in a ConnectWise Agreement Addition. These updates are done nightly, meaning that whenever your billing cycle falls, the Agreement
Addition will have up-to-date counts.
5.21.1
Preparing ConnectWise
1. Create a new Product for each CanIt service you offer. The product names must be as follows;
you only need to create those products that you are actually using.
• CanIt-Inbound for inbound email filtering.
• CanIt-Outbound for outbound email filtering.
• CanIt-SecureMessaging for secure messaging.
• CanIt-Archiver-n for archiving with a retention time of n months. You need to
create one CanIt-Archiver-n Product for each retention time you offer.
96
See Figures 5.24 and 5.25 for examples of how to create the Products within ConnectWise.
Figure 5.24: CanIt-Inbound ConnectWise Product
Figure 5.25: CanIt Product List
97
98
2. Set up an Integrator Login ID and Password
Under System : Setup Tables : Integrator Login, create a login for CanIt-Domain-PRO to access the API. The login that you create must be able to access the following APIs: Managed
Services API, Company API, Product API, Reporting API, System API and Agreement API.
See Figure 5.26.
Figure 5.26: Integrator Login ID Setup
99
3. Create a Management IT Solution for CanIt-Domain-PRO billing. Under System : Setup Tables : Management IT Solution List, create a Management IT Solution. The name must be
CanItBilling and the Management IT Solution should be Custom. See Figure 5.27.
Figure 5.27: CanItBilling Management IT Solution Setup
100
4. Set up Managed Devices Integration. Under System : Setup Tables : Managed Devices Integration List, add a CanItBilling entry with the solution set to CanItBilling. The
Integrator Login should be set to the login name you made in Step 2 earlier. See Figure 5.28.
Figure 5.28: CanItBilling Managed Device Integration Setup
101
5. Create an Agreement for your customer, if there isn’t one yet. See Figure 5.29.
.
Figure 5.29: Connectwise Agreement
102
6. Create a new Agreement Addition (if one does not yet exist) for each CanIt product that you
will bill for. See Figure 5.30.
.
Figure 5.30: Connectwise Agreement Addition
5.21.2
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Preparing CanIt-Domain-PRO
1. In your main realm, click on Setup and then ConnectWise® Integration. The ConnectWise
setup page appears (Figure 5.31):
Figure 5.31: ConnectWise Setup - Main Realm
In the main realm, all you should enter are:
• ConnectWise Web Site URL: the URL for accessing the ConnectWise API.
If you are unsure what it is, please contact your ConnectWise administrator or ConnectWise technical support.
If your regular URL is something like na.myconnectwise.net, then the API URL is probably
api-na.myconnectwise.net/v4 6 release/apis/2.0.
• ConnectWise Company for Login: The company name you use to log into ConnectWise.
• ConnectWise Username for Login: The username you created in Step 2 in Section 5.21.1.
• ConnectWise Password: The password you created in Step 2 in Section 5.21.1.
• Agreement Name: You can fill in a default Agreement Name to use for all of your billing
purposes.
• Billing Metric: Choose Addresses if you are billing based on the number of email addresses, or Streams if based on streams.
• Bill for Subrealms as Well: Set to Yes if you want to bill a realm for its own mailboxes
and those of its subrealms, or No if you only want to bill for mailboxes within the specific
realm.
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• Bill Customer: This setting allows you to override the BillCustomer flag; select one of
Billable (the default), DoNotBill or NoCharge.
• Unit Price: You may optionally override the unit price by entering a decimal number.
• Unit Cost: You may optionally override the unit cost by entering a decimal number.
You should not fill in anything for the Company Name Associated with this Realm since this is
specific to each customer being billed.
2. For each customer realm that should be billed, switch into that realm and click Setup and then
ConnectWise® Integration. In this page, enter the Company Name associated with the realm;
it must exactly match the Company name in ConnectWise. You can also override other settings
such as Agreement Name, Billing Metric, Bill for Subrealms as Well, Bill Customer, Unit Price
and Unit Cost, if necessary. Also, make sure the Agreement Name matches the Agreement you
set up in Step 5 in Section 5.21.1.
You should test the connectwise settings by enabling “Run a live test of these settings against
ConnectWise” and “Update AgreementAddition data on ConnectWise”. Then click Submit
Changes. If all goes well, the test results will look something like Figure 5.32.
Figure 5.32: ConnectWise Test Results
Chapter 6
CanIt-Domain-PRO Administration
6.1
Note:
Global Settings
The first administrative task you should undertake is to set up global settings. Click on the Administration link. You will see the global settings screen:
Figure 6.1: Global Settings
Note that the Basic Setup Wizard (Section 5.3.1) populates some of these settings. The “ID” column
is a unique identifier for each setting; it is not used except as a convenient way for Roaring Penguin
support personnel to indicate a particular setting over the phone.
The global settings have the following meanings:
G-1100
Maximum size of message to scan for spam (kB) Spam-scanning can be very slow on large
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CHAPTER 6. CANIT-DOMAIN-PRO ADMINISTRATION
messages. If a message comes in that is larger than this threshold, CanIt-Domain-PRO attempts
to reduce its size by removing non-text attachments before feeding the message to the scanning
engine. If this succeeds, the reduced message is scanned. If the message is still too large even
after the reduction, it is not scanned for spam.
Handling for messages containing viruses If you have a virus-scanner compatible with
CanIt-Domain-PRO, this setting controls how CanIt-Domain-PRO deals with virus-bearing
messages. Hold holds the message in the quarantine for approval (or tags the message if the
stream is in tag-only mode.) Accept permits the message to pass, while Reject rejects it with
an SMTP failure code. Finally, Discard simply discards the message. We recommend setting
this option to Discard.
G-2400
Note: This setting may be overridden on a per-stream basis.
Expire statistics after this many days Once a day, a cron job removes old entries from the
statistics table. By default, CanIt-Domain-PRO keeps statistics for 10,000 days (around 27
years), but you can lower this setting to as low as 90 days if you do not want to keep old
statistics around.
G-1500
Number of hours to keep detailed statistics CanIt-Domain-PRO keeps very detailed statistics for a limited time. This setting lets you adjust the length of this time.
G-1550
Expire old data after this many days Once a day, a cron job purges old messages, log entries
and incidents from the database. We recommend retaining at least 14 days’ worth of data,
although you might want to lower this on a busy mail server. Note: This setting is the number
of days from the creation of the incidents being expired, regardless of whether or when they
were marked as spam or non-spam.
G-1600
Remember change history for this many days Most CanIt-Domain-PRO web pages have a
“Show Changes” link that lets you see changes made to rules and settings. This setting specifies
how long change history should be retained. It may be set to any integer from 45 to 10000 and
defaults to 732 days (about two years).
G-1610
Expire messages marked as spam after this many days This setting controls when the cron
job expires messages you have marked as spam. Note that it only applies to closed incidents—
that is, messages that have not only been marked as spam, but have also actually been rejected
by CanIt-Domain-PRO.
G-1700
Expire messages marked as non-spam after this many days This setting controls when the
cron job expires messages you have marked as non-spam. Note that it only applies to closed
incidents—that is, messages that have not only been marked as non-spam, but have also actually
been delivered by CanIt-Domain-PRO.
G-1800
Number of hours to cache address-to-stream lookups As mentioned in Section 2.4,
address-to-stream mappings may be cached in the Address Mapping Table. This setting
specifies for how long cached entries remain valid.
G-4010
Number of hours before refreshing cached address-to-stream lookups If a cached address
is older than this many hours, CanIt-Domain-PRO attempts to perform an address-to-stream
G-4015
6.1. GLOBAL SETTINGS
107
mapping to refresh the cached entry. If the lookup fails with a temporary failure, CanIt-DomainPRO does not update the cached entry, but will continue to use it until it expires as per setting
G-4010. If the lookup succeeds, CanIt-Domain-PRO updates the cached entry. If it fails with a
“No such user” result, CanIt-Domain-PRO deletes the cached entry.
Time in hours to delay messages with Delayed Attachments If you use the Delayed Attachments feature, this setting controls the length of the delay.
G-4050
Number of days to keep mail signatures for Bayesian analysis This setting specifies how
long after a message first arrives a user may vote on whether it is spam or non-spam.
G-4800
Number of generations before cleaning common Bayes tokens CanIt-Domain-PRO
periodically cleans old data out of the Bayes database. This setting controls how long
CanIt-Domain-PRO retains a token that has been seen frequently, but not recently. We
recommend leaving it at the default value.
G-4900
Number of generations before cleaning uncommon Bayes tokens CanIt-Domain-PRO periodically cleans old data out of the Bayes database. This setting controls how long CanItDomain-PRO retains a token that has been seen infrequently and not recently. We recommend
leaving it at the default value.
G-5000
Users must opt in to anti-spam scanning? If you set this to Yes, then users must explicitly
opt-in to anti-spam scanning. If users do not opt-in, their mail is simply passed through unchanged. If you set this to No, then all users are implicitly opted-in. They can, however,
explicitly opt out if they choose.
G-4020
Users must be approved for anti-spam scanning? If you set this to Yes, then the CanItDomain-PRO administrator’s approval is required before a user can opt in to anti-spam scanning. If you are selling anti-spam scanning as a value-added service, you should set this to Yes.
If anti-spam scanning is part of your basic service, set it to No.
G-4030
Note that opting in and opting out is done on a per-stream basis. Usually, a stream corresponds
to a user, but it is possible for a stream to correspond to more than one user, and for a single
user to be responsible for more than one stream.
Minimum size of spam corpus for Bayesian analysis CanIt-Domain-PRO will not use
Bayes data until at least this many messages have been trained as spam.
G-4300
Minimum size of non-spam corpus for Bayesian analysis CanIt-Domain-PRO will not use
Bayes data until at least this many messages have been trained as non-spam.
G-4400
Whitelist users who use SMTP authentication If your version of Sendmail is compiled to
support the SMTP AUTH extension, you can whitelist mail from authenticated senders by setting this to Yes. (The default is No.) In this case, mail from authenticated users will not be
scanned for spam (but will still be scanned for viruses and bad filename extensions or MIME
parts.)
G-3600
Note:
CanIt currently cannot preserve SMTP AUTH-based whitelisting when messages are streamed.
Thus, if an AUTH’ed user sends mail to recipients in more than one stream, the whitelisting
will not be applied.
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Store both raw and decoded messages in incident database Some e-mail messages are obscured using Base64 encoding or some other encoding scheme. If you change this setting to Yes,
CanIt-Domain-PRO stores both the “raw” and “decoded” message in the incident database. This
lets you view encoded messages more reliably, but approximately doubles the disk space used
by the incident database. If you set it to No (the default), CanIt-Domain-PRO stores only the
raw message.
G-3900
The message display Web page can decode some encoded messages, but it is not completely
reliable. If you need a completely reliable way to view encoded messages, you should change
this setting to Yes.
Obscure To, Cc and Bcc fields for non-root users Because CanIt-Domain-PRO stores messages that hash identically only once, the To:, Cc: and Bcc: headers of messages may leak
recipient information to other recipients of the message. To hide this information, change this
setting to Yes.
G-4000
Users authenticated by external means default to simple GUI? If you set this to Yes, then
users who authenticate via an external authentication mechanism have a much simplified interface to CanIt-Domain-PRO by default. This simplified interface is described in Chapter 10.
G-4060
Switching to expert mode cancels stream inheritance If you use the Simple Interface
(Chapter 10), then you may wish to cancel inheritance whenever a user selects the expert interface. In that case, change this setting to Yes. That is, if a user has selected a particular
spam-scanning level in the Simple Interface, then when they switch to Expert Interface, the selected level is no longer used—instead, individual settings are used that do not depend on any
of the preconfigured spam-scanning settings.
G-4075
Support the Sendmail ‘plus hack’ for streaming Some Sendmail configuration files allow
users to add a “+” sign followed by arbitrary text to their user names, and use the resulting
e-mail addresses for various purposes such as filtering e-mail. If you change this setting to Yes,
then CanIt-Domain-PRO ignores a “+” sign and any following text after the user name part
when mapping e-mail addresses to streams.
G-4080
Note that if you use the “Program” method to stream e-mail, the “+” sign and any following text
is retained; it is up to your program to implement the sendmail “plus hack” if you choose.
Scan for viruses prior to streaming incoming mail If you know for sure that you always
want to reject or discard viruses, regardless of any per-stream settings, then change this setting
to Yes. It causes any viruses to be discarded or rejected (according to the global virus-handling
setting) before any streaming takes place. If a virus comes in for more than one recipient, this
can greatly reduce the load on CanIt-Domain-PRO. Note that the global virus-handling setting
must not be set to Hold/Tag for this setting to take effect.
G-4090
Timeout in seconds for Verification Server queries If you are using the Verification Server
feature, CanIt-Domain-PRO will time out Verification Queries according to the value of this
setting. You should keep it reasonably low so that a slow or dead verification server does not
interfere with delivery to other domains.
G-4100
To make your changes permanent:
6.2. SRS (SENDER REWRITING SCHEME)
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• Click on Update Global Settings
6.2
SRS (Sender Rewriting Scheme)
In order to avoid spurious SPF failures when CanIt-Domain-PRO forwards mail to a back-end
server that performs SPF checking, you can enable Sender Rewriting Scheme (see http://en.
wikipedia.org/wiki/Sender_Rewriting_Scheme for a description of Sender Rewriting
Scheme.)
To enable Sender Rewriting Scheme, you must perform the following steps:
• Pick a domain to use for the SRS addresses. This domain should not be currently in use for
anything else. We recommend creating a subdomain of your existing domain solely for use
with SRS. For example, if you own the domain example.com, then srs.example.com
would be a good choice.
• Publish MX records for the SRS domain that point to the CanIt-Domain-PRO scanner or scanners.
• Under Administration, enter the SRS domain as the value of G-11000 SRS Domain
• If and only if you are not running a CanIt-Domain-PRO appliance, perform the following steps:
1. Update the Sendmail access map to permit relaying for the SRS domain.
2. Add a mailertable entry for the SRS domain and set the mailer to local:srshandler
3. Create
a
Sendmail
alias
directing
srshandler
"|/usr/share/canit/scripts/canit-srs-bounce-handler"
to
If you are running a CanIt-Domain-PRO appliance, the above steps are done for you automatically.
Additionally, you must specifically enable SRS on a per-stream basis (following the usual CanItDomain-PRO inheritance rules.) To turn on SRS for a stream, enable setting S-930 “Enable SRS
(Sender Rewriting Scheme)” under Preferences : Quarantine Settings.
Note:
SRS requires Sendmail 8.14 or newer. If you are not running a CanIt-Domain-PRO appliance, make
sure you have a new enough version of Sendmail.
Once SRS is enabled, CanIt-Domain-PRO will rewrite envelope senders that receive SPF “pass” to
addresses within the SRS domain. CanIt-Domain-PRO will also handle bounces to those addresses,
restoring the original recipient.
Here are a few items to note about SRS:
• CanIt-Domain-PRO does not apply SRS to mail that was forced into a stream by a Known
Networks entry. Such mail is typically outbound mail; in this case you should simply include
the outbound CanIt-Domain-PRO relays’ IP addresses in the domain’s SPF record.
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• If you have back-end servers that forward inbound mail back out via CanIt-Domain-PRO (this
can happen, for example, if some users on the back-end server configure their accounts to forward everything to Gmail or to Hotmail) then you should enable SRS on the inbound mail for
those users.
• CanIt-Domain-PRO applies SRS only if the original inbound mail received and SPF “pass”.
6.3
Note:
Real-Time DNS Blacklists
Both Sendmail and CanIt-Domain-PRO can make use of DNS-based real-time blacklists. These blacklists allow you to look up the IP address of a host in a special DNS domain, and take action if the host
is blacklisted.
You can configure Sendmail to use DNS-based blacklists directly, but you may prefer to handle this
with CanIt-Domain-PRO, because CanIt-Domain-PRO allows you to hold or score messages from
hosts on the blacklist rather than outright rejecting them.
6.3.1
Entering the Master List of DNS RBLs
To use DNS-based RBLs, you first enter a master list of RBLs that CanIt-Domain-PRO can potentially
use. To do this, click on Administration and then Master RBLs. The Master RBLs page appears:
Figure 6.2: Master RBLs
To enter an RBL:
1. Enter the domain in the RBL Domain box.
2. Enter a brief (but meaningful) description in the Description box.
3. Enter a short tag in the Tag box. This tag is used in the mail log and incident reports to identify
the RBL. If you leave it blank, CanIt-Domain-PRO will construct a unique identifier for the
RBL based on the domain, type and data.
4. Select how the RBL is to be used:
6.3. REAL-TIME DNS BLACKLISTS
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(a) A Block RBL is used to block unwanted mail. Users will be able to create “Ignore”,
“Hold/Tag”, “Reject” or “Score” RBL rules. Any “Score” rule will have to have a nonnegative score.
(b) An Allow RBL is used to list known good mail servers. Users will be able to create
“Ignore” or “Score” rules, but any “Score” rule will have to have a non-positive score. In
addition, no extra greylist delay may be created for an Allow RBL.
5. Select the type of addresses listed by the RBL:
(a) If you know that the RBL lists only IPv4 addresses, set the Address Family to IPv4.
(b) If you know that the RBL lists only IPv6 addresses, set the Address Family to IPv6.
(c) If the RBL lists both IPv4 and IPv6 addresses, set the Address Family to Both IPv4 and
IPv6. If you are not certain whether or not the RBL lists IPv6 addresses, the “Both” setting
is safest.
6. Select the type of the RBL:
(a) If the RBL is considered to be “hit” if any record is returned, set the type to normal. Most
DNS-based blocklists are of this type.
(b) If the RBL returns specific A records to indicate a hit, set the type to match and enter the
A record that indicates a hit in the Data field. As a special case, you can use an X in place
of an octet to allow a wildcard match. For example, a data field of 127.0.X.3 would
match an A record of 127.0.0.3, 127.0.1.3, 127.0.55.3, etc.
(c) If the RBL returns information in a bitmask in the returned A record, set the type to
mask and enter the mask (for example, 0.0.0.4) in the Data field. A mask-type RBL is
considered to be hit if the returned A record bitwise-ANDed with the data field returns
non-zero.
To delete an RBL, enable the checkbox beside the entry you wish to delete and click Submit Changes.
Deleting a master RBL also deletes all RBL rules that refer to it.
You can change the timeout for RBL lookups by adjusting the value in the Timeout in seconds for
DNS-RBL lookups box.
The master RBL list is merely a list of all the RBLs that CanIt-Domain-PRO can potentially use. To
actually set up RBL rules, please see the User’s Guide. RBL rules can be created on a per-stream
basis, so different streams can elect to use none, some or all of the predefined Master RBLs.
Note:
Various RBLs have different terms-of-service. Some require licensing or payment; please be sure you
are allowed to use an RBL before entering it into CanIt-Domain-PRO’s RBL list.
6.3.2
combined.bl.rptn.ca
Roaring Penguin Software Inc. publishes for DNS-based lists for CanIt-Domain-PRO customers.
These lists are automatically entered into the Master RBL list (but no rules are created automatically.)
The four lists are:
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• The Greylist-Stumbler list. These are machines known to have trouble getting past greylisting.
The machines are very likely compromised PCs. We recommend making a rule to add one
point for machines on this list, and also to extend the greylist period (if you use greylisting) to
60 minutes.
• The Dictionary-Attacker list. These are machines known to send mail to many nonexistent
addresses. We recommend a rule to add one point for machines on this list.
• The Spam-Source list. These are machines known to send spam and relatively little non-spam.
We recommend adding three points for machines on this list.
• The Good list. These are machines that send relatively little spam, quite a lot of non-spam, and
have no trouble with greylisting or sending to nonexistent recipients. We recommend subtracting 0.5 points for machines on this list.
Note:
The combined.bl.rptn.ca list requires a secret token for lookups to succeed; this token is changed
once a day. CanIt-Domain-PRO automatically obtains and uses the token for as long as your support
term is in force. This means that you cannot use the list outside of CanIt-Domain-PRO. If you do a
high volume of lookups, please contact Roaring Penguin Software to arrange for a zone transfer via
rsync.
6.4
Note:
Phishing URLs
The ability for end-users to vote URLs as malicious is available only if you have enabled CanIt Storage
Manager (Chapter 16)
CanIt-Domain-PRO maintains a list of URLs that are known to be malicious or to have been used in
phishing messages. There are two sources of these URLs:
• A large list is distributed by Roaring Penguin to each CanIt-Domain-PRO installation. Your
RPTN credentials provide access to this list.
• Each CanIt-Domain-PRO administrator can additionally maintain a local list of phishing URLs.
6.4.1
Malicious URL Votes
When end-users reject an incident from the quarantine page, they can choose merely Reject message
or the stronger Reject and Report Phish/Fraud. The latter presents users with a list of URLs in the
rejected message and asks them to indicate which URLs they believe to be malicious. Each such URL
is entered as a phishing URL vote.
You can review phishing URL votes by clicking on Administration and then Phishing URLs. The
Phishing URL Votes page appears:
6.4. PHISHING URLS
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Figure 6.3: Phishing URL Votes
This page shows all of the URLs that users have indicated are malicious. The various columns in the
display are:
• URL — a normalized version of the URL with any leading http: or https: stripped. Note
that URLs longer than 40 characters are truncated and an elipsis (...) is placed after them; hover
the mouse pointer over the URL to see the full URL.
• Votes — the number of times the URL has been voted as malicious.
• In Phishing List? — Set to “No” if the URL is not in the central list of known phishing URLs,
or “Bad” if it is. If the URL has query parameters (for example: example.com/foo?x=1)
and the base URL example.com/foo without query parameters is in the central list, then
this column will contain “Base URL Bad”.
If the URL is in the known phishing list, then the source is indicated as local or RPTN:*.
local means the URL was added by the local CanIt-Domain-PRO administrator; RPTN:*
means it came from the central Roaring Penguin list. The specific text after RPTN: provides
additional detail about the source of the URL.
• Last Vote — the date the URL was last voted as being malicious.
• Action — a list of actions to take against the URL. Possibilities are:
– Do Nothing — don’t take any action.
– List URL as Bad — enter the URL into the known phishing URL list, marked as malicious.
– List base URL as Bad — remove the query parameters, if any, from the URL and enter it
as a malicious URL in the known phishing URL list.
– List URL as OK — explicitly indicate that the URL is not malicious. You can use this if,
for some reason, you need to override a URL marked as malicious in the central Roaring
Penguin list.
Note that any URL you enter into the list of known phishing URLs will be set to expire after
120 days. You can alter this expiry date as described in Section 6.4.2.
• Delete? — this permits you to delete all votes relating to the URL. Note that if the URL is in
the known phishing URL list, deleting it from the Phishing URL Votes page does not remove it
from the list. It merely deletes all users’ votes pertaining to the URL.
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If you take action against phishing URLs or delete any, click Submit Changes to make your changes
take effect.
Filtering the List of Phishing URL Votes
You can filter the list of phishing URL votes displayed as follows:
• Enter a string in the “Entry Contains:” filter box to restrict URLs to those containing a particular
string.
• Enter a positive integer in the “Minimum Votes:” filter box to restrict URLs to those with at
least that many votes.
• Select one of “Any”, “Yes” or “No” from the “In Known-Phishing List?” pulldown to restrict
the URL display to those which meet the filter condition.
Once you have created filter conditions, click Filter to apply them.
6.4.2
Known Phishing URLs
To see the entire list of URLs known or suspected to be malicious, click on Administration and then
Phishing URLs. In the Phishing URL Votes page, click on Known-Phishing List in the third-level
menu. The Known Phishing URLs page appears:
Figure 6.4: Known Phishing URLs
The list of phishing URLs has eight columns:
• URL — a normalized form of the URL. Note that URLs longer than 40 characters are truncated
and an elipsis (...) is placed after them; hover the mouse pointer over the URL to see the full
URL.
• Votes — the number of times a URL has been voted as malicious by a local user.
• Status — “Bad” if the URL is considered malicious; “Good” if it is considered harmless.
• Source — the source that determined the URL to be malicious. Possible values for Source are:
6.4. PHISHING URLS
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– local — the URL was marked as malicious by the local CanIt-Domain-PRO site administrator.
– RPTN:APER — the URL was considered malicious by the Anti-Phishing Email Reply
project at https://code.google.com/p/anti-phishing-email-reply/.
– RPTN:Phishtank — the URL was considered malicious by the Phishtank project at
http://www.phishtank.com/.
If Roaring Penguin adds additional feeds of malicious URLs, there may be additional values for
Source, but all of them will start with RPTN:.
• Last Vote — the time of the most recent vote by a local user (if there was one) that the URL
was malicious.
• Expiry — the date when the URL will expire and be auto-deleted from the list. By default, local
entries expire 120 days after they are created. RPTN entries do not expire, but are removed if
the URL is removed from the central RPTN lists maintained by Roaring Penguin.
• Action — an action to take against the URL. Possible actions are Do Nothing, List URL as
Bad and List URL as OK, all of which are self-explanatory.
• Delete? — a checkbox for deleting a URL from the known phishing URL list. Note: If you
delete a URL with a source other than local, it will reappear next time CanIt-Domain-PRO
updates its URL list from Roaring Penguin’s data feed.
If you make any changes (taking action against URLs, changing the expiry date or deleting any URLs),
click Submit Changes to make them take effect.
If you wish to add URL that is not currently in the Known Phishing URLs list, you can enter it in the
top row in the URL column and hit Submit Changes to add it to the list manually.
Filtering the Known Phishing URL List
You can restrict which URLs are displayed by entering text into the “Entry contains:” and/or “Source
Contains:” filter boxes and clicking Filter.
6.4.3
Delaying Messages because of local Phishing Votes
There can be a significant delay between the time a URL is voted on by end-users as fraudulent and
the time the administrator adds it to the Known Phishing list. To mitigate problems caused by this
delay, CanIt-Domain-PRO allows you (on a per-stream basis) to delay messages once the URLs in
them have a certain number of phish votes.
Under Preferences : Quarantine Settings, set S-1630 to the minimum number of votes to trigger a
delay. A value of 0 disables the feature. We recommend a value of at least 5 so that messages are
unlikely to be delayed because of a couple of incorrect votes.
On that same page, set S-1640 to the number of hours to delay the message.
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If a message comes in containing a URL that has at least as many phish votes as the S-1630 setting,
then it is put into a special stream called @@DELAYED in the recipient’s realm. After the number
of hours specified in S-1640, the message will automatically be released from @@DELAYED and rescanned.
We recommend setting a notification address in the @@DELAYED stream to notify administrators
hourly. That way, they can check that stream’s quarantine and reject malicious messages before they
are released. Administrators can also take the opportunity to add malicious voted-on URLs to the
Known Phishing URL list.
6.5
Users
CanIt-Domain-PRO maintains its own table of users. You should enter users into this table to create
CanIt-Domain-PRO administrative users, or users with different privileges from the default (for example, a demo user.) Click on Administration and then Users to set up users. You will see the user
management screen.
Figure 6.5: Users
User-ID or E-Mail column contain that string.
We recommend using the form [email protected] for user names. Users whose names follow that
format will be placed in the appropriate realm, as determined by looking up domain.com in the
Realm Mapping Table. A user name of the form user without a domain will normally be placed
in the base realm. (However, a user can specify a particular realm to log in to by logging in as
realm:user.)
6.5. USERS
6.5.1
117
User Privileges
When a user logs in to CanIt-Domain-PRO, he or she can see a single stream at a time. Every
user always has access to a stream that (usually) has the same name as his user name. The CanItDomain-PRO administrator can give users permission to see additional streams. For example, the user
janedoe always has access to the stream janedoe. However, if she manages a mailing list called
joke-list, you have two options:
1. You can stream messages for the list to janedoe, so she has only a single spam quarantine to
consider.
2. You can create a new stream called joke-list and give access to that stream to janedoe.
In this way, she can use different settings, blacklists and whitelists for the list than she does for
her personal e-mail.
Each CanIt-Domain-PRO user has two special privileges, which can be on or off:
• A user with root privilege can add, edit and delete other users. A user with root privilege in
the base realm has overall System Administrator privileges. A user with root privilege
in any other realm has Realm Administrator privileges. The overall System Administrator can
see (and create) users in other realms. Realm Administrators can only create users in their own
realms.
• A user with write privilege can mark messages as spam or not-spam, and can blacklist and
whitelist hosts, domains and senders. A user without write privilege is called a read-only user
and cannot make any changes whatsoever. A read-only user can look, but not touch.
Note that CanIt-Domain-PRO allows for additional flexibility in controlling which parts of the Web
interface are available to various users. For details, see Chapter 9.
6.5.2
Adding a User
To add a user, click on the Add User link. The Add User screen appears:
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Figure 6.6: Add User
• Enter the user-ID of the user in the User-ID box.
• Select the realm for the new user from the Realm pull-down menu or enter it into the realm box.
If you leave the realm blank, then a realm will automatically be assigned based on the user-ID.
If the user-ID looks like an e-mail address, the realm is chosen by mapping the domain-name
part of the user-ID to a realm.
• To set the user’s e-mail address, enter it in the E-Mail field. (If CanIt-Domain-PRO knows a
user’s e-mail address, the “Locked Addresses” feature can be used.)
• Enter a password for the user in the Password and Confirm Password fields.
• If you set Locked Password? to Yes, then the user will have a “locked” password and will not
be able to log in. However, if you have configured an alternate user authentication method, the
user will be able to log in using a password that the alternate method accepts.
• If you only want the user to have read-access to the spam quarantine, set Write Access? to No.
• If you want to make the user an administrator in his realm, set Has Root Access? to Yes.
Once you have filled in the fields, click Add User to add the user.
Note:
Both user-names and passwords are case-sensitive; a used named user1 is completely different from
one named User1.
6.5.3
Editing a User
To edit a user, click on the User-ID on the user management screen. You will see the user-editing
screen.
6.5. USERS
119
Figure 6.7: Edit User
• The user’s realm may be displayed, but it cannot be edited once the user has been created.
• To set the user’s e-mail address, enter it in the E-Mail field.
• If you wish to change the user’s password, enter it in the Password and Confirm Password
fields. If you leave these fields blank, the password will not be changed.
• If you set Locked Password? to Yes, then the user will have a “locked” password and will not
be able to log in. However, if you have configured an alternate user authentication method, the
user will be able to log in using a password that the alternate method accepts.
• Adjust the write-access privilege by setting the Write-Access? checkbox appropriately. (If you
are editing the currently logged-in user, you can’t change the Write-Access setting.)
To make the changes take effect, click Submit Changes.
6.5.4
Deleting a User
If there is more than one user, a Delete checkbox appears beside those users that can be deleted.
Enable the checkbox and then click Submit Changes to delete the selected user or users. Note that it
is not possible to undo the deletion!
Note that if you delete a user, he may still have access if he can be authenticated using an external
authentication mechanism.
6.5.5
Granting Access to Streams
If you wish to grant a user access to additional streams, click on the Edit Accessible Streams button
(Figure 6.7). The following page will appear:
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Figure 6.8: Granting Access to Streams
To grant access to a stream, enter the stream name in the input box and click Add Stream. To revoke
access to a stream, enable the Delete checkbox next to the stream name and click Delete Selected
Streams. If you grant access to a stream named * (a single asterisk), then the user is given access to
all streams in his or her realm.
Note that a user always has access to a stream with the same name as his user name, and this access
cannot be revoked. Also, the CanIt-Domain-PRO administrator can access any stream, regardless of
the settings on this page.
6.5.6
Switching Users
CanIt-Domain-PRO permits an administrative user to switch to another user-ID. This is useful if you
want to see the interface exactly as another user would see it. A realm administrator can switch to any
user within his own realm or any realm in the subtree under that realm.
To switch users:
1. Click Administration : Switch User
2. Enter the user you wish to become in the User-ID box.
3. Enter the stream in which the user should be placed after the switch in the Stream box. Note
that CanIt-Domain-PRO does not run the normal user-lookup to determine a user’s home stream
when you switch users; hence, you may need to enter the home stream explicitly.
4. If you own subrealms, you will be asked for the realm of the new user. Note that CanIt-DomainPRO does not attempt to deduce the realm based on the User-ID; you need to explicitly select a
realm in the Realm field.
5. Click Submit Changes. You are now logged in as the new user.
Note:
Once you switch users, there is no going back. In most cases, you have to log out and log back in
again to become the original user. Also, if you are logged in as a read-only user, then you remain
read-only no matter which user you switch to.
6.6. PERMITTING USERS TO OPT IN
6.6
121
Permitting Users to Opt In
In the CanIt-Domain-PRO global settings (Section 6.1), the CanIt-Domain-PRO administrator can
control:
• Whether or not people are permitted to opt-in to spam scanning.
• Whether the default setting is opt-in or opt-out.
There are three useful combinations:
1. Permit everyone to opt-in, and have the default be opt-in.
2. Permit everyone to opt-in, and have the default be opt-out.
3. Permit only selected people to opt-in, and have the default be opt-out.
In the first two cases, the administrator need not do anything special. In the third case, you must add
entries to the Stream Approval Table. Click on Administration and then Opt Others In/Out to see
this table:
Figure 6.9: Stream Opt-In Approval
If the “Approved?” column is checked, then the stream may opt in to spam scanning. If it is not
checked, then the stream may not opt in to spam scanning.
If the “Opted-In?” column is checked, the stream is currently opted in to spam scanning. Otherwise,
it is not.
To add a stream to the table, enter the stream name in the input box and set “Approved?” and “OptedIn?” appropriately. Then click Submit Changes.
To edit existing streams, adjust “Approved?” and “Opted-In?” appropriately and click Submit
Changes. To delete a stream from the opt-in table, enable the Delete? checkbox on the appropriate row and click Submit Changes.
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If the default setting is to permit anyone to opt in to spam scanning, you can nevertheless exclude
particular streams from being able to opt in by entering them in the Stream Approval Table and turning
off the “Approved?” checkbox.
In order for spam-scanning to occur, a stream must be both approved and opted-in. If the stream is not
found in the Stream Approval Table, then the defaults are taken from the Global Settings.
Stream column contains that string.
6.7
Groups
For the purpose of granting permissions, CanIt-Domain-PRO allows you to create groups. A group is
simply a collection of users.
To edit groups, click on Administration and then Groups. The Groups Page appears:
Figure 6.10: Groups
6.7.1
Creating, Deleting and Editing Groups
To create a new group:
1. Enter the name of the group in the Group box.
2. Enter a description of the group in the Description box.
To delete an existing group:
1. Enable the Delete checkbox for the group you want to delete.
To edit a group:
6.8. VIEWING ACTIVE STREAMS
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1. Click on the Edit link next to the appropriate group. The Group Members page appears:
Figure 6.11: Group Members
2. Enter new members (one per line) in the Member text area.
3. If you want to delete existing members, enable the appropriate Delete checkbox.
Note:
External authentication methods can affect group membership. See Chapter 7 for details.
In the Groups Page (Figure 6.10), click on Permissions to edit the permissions associated with the
group. Permissions will be discussed in detail in Chapter 9.
6.8
Viewing Active Streams
The CanIt-Domain-PRO administrator can look at all the streams with entries in the incidents table.
To do this, select Administration and then See Active Streams. The Active Streams Page appears:
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Figure 6.12: Active Streams
6.8.1
Definition of an Active Stream
A stream is considered “active” if it has at least one message in the quarantine (pending, spam or
non-spam) or has any rules, blacklists or whitelists defined.
6.8.2
The Active Stream Display
The columns in the display are:
Stream The name of the stream. Each stream name is a hyperlink; if you click on the link, you will
switch streams to that stream.
Pending The number of pending messages in the stream’s quarantine.
Spam The number of spam messages in the stream’s quarantine.
Non-Spam The number of non-spam messages in the stream’s quarantine.
Opted-In? Set to Yes if the stream is both approved for anti-spam scanning and opted-in; set to No
otherwise.
Delete A column of links for deleting streams.
Stream column contains that string.
6.9. FILTERING OUTBOUND MAIL
6.8.3
125
Deleting a Stream
To delete a stream, click on the Delete link in the Active Streams page. Then click on Yes, delete it!
to confirm deletion. Deleting a stream deletes all incidents, rules, settings, etc. associated with the
stream.
6.9
Filtering Outbound Mail
Some organizations like to add boilerplate disclaimers to outbound mail. CanIt-Domain-PRO can
achieve this by streaming all outbound mail to an “outbound” stream, and adding boilerplate options
for that stream.
One way to stream all outbound mail to a particular stream is to set up your domain mappings as
follows:
• All of your own domains (that is, domains considered “internal”) should have mappings set up.
The mappings could be ChopDomain, Sendmail, or whatever, as long as the mappings exist.
• The wild-card domain * should have a domain mapping of Database.
• The wild-card address * should have an address mapping mapping it to the stream outbound.
(You can name your outbound stream however you like.)
With these settings, mail for internal recipients will be streamed appropriately, and mail for external
recipients will all be streamed to outbound.
For the outbound stream, enter the appropriate boilerplate to add to outbound messages. You can also
add custom body-matching rules if you want to quarantine mail containing certain words—for example, “Do Not Distribute Externally” Such rules on an outbound stream may help prevent unauthorized
distribution of confidential information.
See also Known Networks (Section 5.7 on page 65) for another way to force outbound mail into a
specific stream. Using Known Networks may be simpler than using address mappings if all your
outbound mail originates from a limited set of IP addresses.
6.9.1
DKIM-Signing Outbound Mail
DKIM, or DomainKeys Identified Mail is a mechanism for proving that a particular organization’s
servers relayed a mail message. More specifically, DKIM uses cryptographic techniques that allow
recipients to validate that a specific domain is indeed associated with the message.
CanIt-Domain-PRO permits you to DKIM-sign outbound mail. Please note that the only way CanItDomain-PRO can validate the origin of a message is to look at the sending IP address. Therefore,
CanIt-Domain-PRO DKIM-signs messages based on a domain being associated with a Known Networks entry with the “Force-to-Stream” parameter (indicating outbound mail) set.
For example, consider this Known Networks entry:
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Figure 6.13: Known Network with Associated Domains
In this example, CanIt-Domain-PRO will permit DKIM signing of a message:
• That has a From: header sender in the domain example.com or example2.net
• Providing also that the message originates from 192.168.7.88/32
In order to DKIM-sign a message, CanIt-Domain-PRO requires a key pair to be generated. A key pair
consists of two cryptographic keys that work together: The private key is a very large number that is
kept secret. It is used to sign a message. The public key is another very large number that is connected
to the private key and must be made public; anyone who has the public key can verify whether or not
a message was indeed signed by the private key. The mathematics of signing is such that although
possession of the public key permits verification that a message is signed, only possession of the
private key permits the actual signing process. Additionally, it is believed that it is infeasible to derive
the private key given only the public key.
A DKIM public key is typically published by creating a special TXT DNS record that contains the
public key and a few ancilliary pieces of information required by DKIM verification software.
Managing DKIM Keys
To DKIM-sign a message from a particular domain, CanIt-Domain-PRO needs a key pair. To generate
a key pair, click on Setup and then DKIM Keys
To add a new DKIM key pair, click on Add New DKIM Key Pair. The DKIM Key Pair page appears:
Figure 6.14: Adding a DKIM Key Pair
Enter a domain name and click Save. Note that the domain you enter must be associated with at least
on Known Networks entry. Additionally, the domain must be within the current realm.
6.9. FILTERING OUTBOUND MAIL
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The DKIM selector defaults to “canit”, but you can use any selector you like as long as it is at most
16 characters long and can appear as a legal domain name component.
Once you have added the key pair, CanIt-Domain-PRO will display information about the key:
Figure 6.15: DKIM Key Details
The information displayed includes the domain name DNS TXT record required to publish the public
key. Please note: DKIM TXT keys are typically quite long. We display them in BIND 9 multi-part
string format. Different DNS software might require the record to be entered in a different format; in
reality, the entire record is one long piece of text. Please consult your DNS provider’s documentation
for more information on the format required for DKIM keys.
To delete DKIM key pairs, click on Setup and then DKIM Keys. Enable the appropriate checkboxes
in the Delete? column and click Submit Changes.
DKIM Selectors
CanIt-Domain-PRO allows you to specify a DKIM selector, but note that any given domain is only
allowed to have one DKIM key. DKIM selectors are useful should you wish to roll over your keys.
Here is an example:
• Suppose you create a DKIM key pair with the selector s201501. CanIt-Domain-PRO creates
the key pair and you publish a DNS record.
• Sometime later, you want to change the key pair because it’s good practice to change keys every
now and then. Within CanIt-Domain-PRO, delete the key pair but leave the DNS record in place
on your DNS server. Then create a new key pair with a selector of (for example) s201506.
Publish that record in the DNS
In this way, old messages can still be verified for as long as you keep the s201501 DNS record
in place, but all new messages will be signed and verified with the new key pair and the selector
s201506.
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Selectively DKIM-Signing Outbound Mail
Sometimes, an organization may not wish to DKIM-sign all of its outbound mail. CanIt-Domain-PRO
lets you selectively sign outbound mail as follows:
When CanIt-Domain-PRO sees an outbound message, it computes the stream that the From: header
address would be in. If, for some reason, it cannot find the stream, it uses the default stream in the
realm of the From: header address.
If the Quarantine Setting S-1050 Enable DKIM Signing for outbound messages originating from
senders in this stream is set to Yes in the stream determined above, CanIt-Domain-PRO DKIM-signs
the message. Otherwise, it does not. This allows you to avoid DKIM-signing bulk messages, automated messages, etc. providing they originate from addresses with their own streams.
By default, S-1050 is set to Yes, so by default outbound mail is DKIM-signed if a key pair is present
and the messages comes from an associated domain of a Known Network.
A Note on some DKIM-Signing Pitfalls
CanIt-Domain-PRO uses software called Sendmail to actually accept and deliver messages. Sendmail may make its own header modifications to messages without CanIt-Domain-PRO’s knowledge,
thereby breaking DKIM signatures. In most cases, programs used to compose email messages do
so in such a way that Sendmail does not need to modify anything and DKIM works fine. But we
recommend testing DKIM with all the mail software your users employ to ensure it generates correct
signatures.
In particular, Sendmail will change a header that looks like this:
From:
Full Name <[email protected]>
to this:
From:
"Full Name" <[email protected]>
Note the additional double-quotes. Most email software generates the header with double-quotes in
place anyway, so Sendmail has no need to modify the header. If your software does not, you’ll need a
way to force it to do that if you wish to have CanIt-Domain-PRO DKIM-sign your messages.
6.10
Copying Rules from One Stream to Another
Occasionally, it is useful to copy or move rules from one stream to another. To do this, click on
Administration and then Copy Rules. The Copy Rules page appears:
6.11. SECONDARY MX HOSTS
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Figure 6.16: Copying Rules
To copy rules:
1. Choose which rules you wish to copy by activating the appropriate check boxes under Objects
to Migrate.
2. Put the name of the stream you want to copy from in the From stream: box.
3. Put the name of the stream you want to copy to in the To stream: box.
4. Select “Preserve Original” or “Overwrite” to handle the case of conflicting rules in the source
and destination streams.
5. Click on Copy Rules to copy rules from the source stream to the destination stream. Move
Rules is similar, but any rule that is successfully placed in the destination stream is deleted
from the source stream.
6.11
Secondary MX Hosts
Secondary MX hosts require special handling by CanIt-Domain-PRO. Secondary MX hosts which relay to the CanIt-Domain-PRO system should always be listed in “Known Networks”, with the options
below checked, as it is usually desirable to modify CanIt-Domain-PRO behaviour as follows:
Note that localhost (127.0.0.1) is always considered a secondary MX host for the purposes below:
Friendly Host When checked, rejected mail is simply discarded rather than being failed with a 5xx
code. This prevents the friendly host from generating backscatter.
Parse Received Headers When checked, CanIt-Domain-PRO trusts the Received: header added by
that connecting host or network. This means that CanIt-Domain-PRO will be able to apply host
checks against the host that submitted the message to your network, rather than against your
secondary MX server.
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Prohibit Blacklisting When checked, CanIt-Domain-PRO ignores any host-blacklists for hosts in
this network. This will prevent locally-generated mail from your secondary MX hosts from being blacklisted. Note that if “Parse Received Headers” is enabled, mail relayed via the secondary
system will show as being from the upstream IP, and blacklists will not be ignored.
Skip RBL Lookups When checked, CanIt-Domain-PRO will suppress DNS blacklist lookups.
Skip Greylisting When checked, CanIt-Domain-PRO will suppress first-time sender checks.
Any machine under your control that you expect to forward mail to your machine should be considered
a secondary MX host. For example, if a number of users have accounts on a machine that forward mail
to your machine using .forward files, you should consider entering that machine as a secondary MX
host.
Also, note that if CanIt-Domain-PRO is able to determine the “real” relay IP by parsing the Received:
headers, and you have enabled this option, then CanIt-Domain-PRO runs all the host checks as usual,
using the real relay IP address. However, these checks are (of necessity) delayed until after the DATA
phase of the SMTP transaction, because CanIt-Domain-PRO does not have the required information
at the MAIL FROM: or RCPT TO: phases.
6.12
Avoiding Backscatter
Under most circumstances, if CanIt-Domain-PRO rejects a message, it responds with an SMTP failure
code. This generally causes the sending relay to mail a failure notification to the original sender.
However, because most spam and viruses have faked sender addresses, you may not want this behavior
for messages relayed from a secondary MX host or for messages split into multiple streams. That’s
because if a message is rejected after having been accepted by one of your mail servers, it’s the
responsibility of the sending server to generate a failure Delivery Status Notification or DSN.
If (as is likely) the sender address is faked, that failure message may arrive at an unsuspecting thirdparty. This is what is known as backscatter.
It is a violation of RFC 821, and is generally considered bad behavior, to silently discard mail; however, many sites are beginning to lump hosts responsible for generating backscatter into the same
category as spammers. Because of this, CanIt-Domain-PRO will not generate a failure notification for
mail from local host or from a designated secondary MX host.
6.13
Test Plugins
Some anti-spam tests are very specific and are implemented as plugins. Currently, CanIt-Domain-PRO
ships with a number of plugins that are described in subsequent sections.
If a plugin matches against a particular message, the plugin is said to have fired.
To configure test plugins, click Rules and then Plugins. The Test Plugins page appears:
6.13. TEST PLUGINS
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Figure 6.17: Test Plugins
For each plugin, you can configure actions to be taken on a per-stream basis (although we recommend
creating rules only in the default stream.)
To configure a plugin:
1. Select the action to be taken if the plugin fires. The action can be one of:
• Ignore — do not use this plugin at all.
• Hold/Tag — hold mail in the quarantine if the plugin fires. (In a tag-only stream, this will
be converted to a tag.)
• Score — add the score in the Score column if the plugin fires.
• Reject — reject the mail if the plugin fires.
2. If you chose Score, enter a decimal score in the Score column.
3. If you wish, you can add a comment in the Comment column
4. Click Submit Changes to make the changes take effect.
6.13.1
The PhishingAddress Plugin
The PhishingAddress plugin consults a dynamically-updated list of e-mail addresses known to be used
in phishing attacks. We recommend configuring it as follows:
• In the default stream, configure the test to add 10 points to the message score. Alternatively,
you may wish to configure it to reject mail.
• If you are routing outbound mail through CanIt-Domain-PRO, then you should be sending outbound mail through a dedicated outbound stream. In that stream, configure the PhishingAddress
plugin to reject mail. If users accidentally reply to a phishing e-mail that somehow got through,
at least by rejecting their replies you will prevent sensitive information from reaching the attackers.
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6.13.2
The PhishingURL Plugin
The PhishingURL plugin consults a dynamically-updated list of URLs known to be used in phishing
attacks. It fires if a message contains one or more URLs on the list.
We recommend configuring the test to add 10 points to the message score. Alternatively, you may
wish to configure it to reject mail.
6.13.3
The OfficeMacros Plugin
The OfficeMacros plugin examines Microsoft Office attachments and fires if they contain macros.
Since office documents containing macros can be extremely dangerous and can be used to spread
malware and ransomware, we recommend scoring this plugin at 3.5. However, if you find there are
too many false-positives, cautiously lower the score.
6.13.4
The OfficeMacro* Open Plugins
Three plugins named OfficeMacroAuto Open, OfficeMacroDocument Open and OfficeMacroWorkbook Open fire if a Microsoft Office document contains a macro with the name Auto Open, Document Open or Workbook Open, respectively.
These macros are often used by malicious software to launch a virus payload. The default and recommended action for each plugin is to score 10 points.
Note that legitimate spreadsheets fairly frequently contain the Workbook Open macro, so you may
cautiously reduce the score for OfficeMacroWorkbook Open, although we recommend doing it on a
case-by-case basis (rather than in the default stream) to limit the risk.
6.14
Emergency Blocking of Delivery Status Notifications
Sometimes, a spammer will process a large spam run and fake the sender address to be within a
domain you control. Faking the sender address as if it comes from an innocent third-party is called a
joe-job.
Unfortunately, in a typical spam run, a large percentage of the recipient addresses are invalid, so the
run creates many delivery failure notifications (officially called Delivery Status Notifications or DSNs).
Because of the faked sender address, all of these notifications come back to you, the innocent thirdparty. These spurious failure notifications are called backscatter and can cause a huge load on your
CanIt-Domain-PRO scanners, as well as a huge annoyance for end-users.
CanIt-Domain-PRO has a feature that allows you to block DSNs for selected domains for a limited
time. This is an emergency measure and should only be used for a limited time in the face of large
amounts of backscatter.
Normally, this feature is disabled. To enable the feature, click on Setup : Features and enable the
Permit Emergency Blocking of Delivery Status Notifications feature.
Next, click on Rules : Block DSNs. The Block Delivery Status Notifications page appears:
6.15. REMOVING ALL RULES AND SETTINGS FROM A STREAM
133
Figure 6.18: Block Delivery Status Notifications Page
To turn on DSN-blocking for a domain:
1. Enter the domain name in the Domain box.
2. Pick an expiry date. The default expiry date is 5 days in the future. CanIt-Domain-PRO will not
let you pick an expiry date more than 30 days in the future.
3. If you wish, add a comment explaining why you are enabling DSN-blocking.
To edit the expiry date and comment for existing entries, change the text in the appropriate boxes and
click Submit Changes
To remove DSN-blocking from a domain, enable the appropriate Delete? checkbox and click Submit Changes.
Note:
DSN blocking applies to all streams in the realm. In this respect, it is different from other entries in
the Rules menu which apply to a particular stream.
6.15
Removing All Rules and Settings from a Stream
On occasion, it may be necessary to delete all rules, blacklists, whitelists, settings, etc. from a stream.
If a novice user has created many such rules and settings, the stream may be unusable and a “factory
reset” advised. To delete all rules and settings from a stream:
1. Switch to the stream in question with the View This Stream button.
2. Click on Rules.
3. Click on the link after the phrase “To delete all rules and stream settings for stream streamname,
click here.”
4. Click Purge Rules to delete all the rules and settings, or Cancel to cancel.
Note:
It is not possible to purge all rules from the default stream.
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6.16
Provisioning Information
CanIt-Domain-PRO keeps track of all the addresses and streams that have received mail in the last 30
days. It can display this information so you can track the usage of the system.
To view provisioning information, click on Administration and then Provisioning. The Provisioning
page appears:
Figure 6.19: Provisioning Information
The rather large provisioning table contains a number of columns. The columns are as follows:
• Realm - the name of the realm. The realm tree starting at the current realm is displayed along
with little arrows to indicate the hierarchical structure. Realm names are links which, if clicked,
display provisioning rooted at that realm.
• Domains - a list of domains mapped to the realm. Each domain name is followed by a green
checkmark and the green letters “MX” if its MX records point to CanIt-Domain-PRO. If the
MX records do not point to CanIt-Domain-PRO, then the domain name is followed by a red X
and the red letters “MX”. Note that MX records are checked once a night by the nightly cron
job, so the information displayed here may be slightly out of date.
If a domain does not correctly validate recipients, the MX indicator is followed by a yellow
hazard sign warning of the problem. Note that provisioning information for non-validating
domains will not be accurate.
• Expiry - the expiry date (if any) associated with the realm.
• Addresses This Realm Only - the number of addresses in the realm that have received email
in the last 30 days.
• Addresses Including Subrealms - the number of addresses in the realm and all of its descendants that have received email in the last 30 days.
• Streams This Realm Only - the number of addresses in the realm that have received email in
the last 30 days.
• Streams Including Subrealms - the number of addresses in the realm and all of its descendants
that have received email in the last 30 days.
6.16. PROVISIONING INFORMATION
135
• Outbound Addresses This Realm Only - the number of outbound addresses in the realm. A
realm is considered to be using outbound filtering if any of its domains is associated with a
Known Networks entry (Section 5.7.) In this case, all of its inbound addresses are counted in
the outbound column. Otherwise, no addresses are counted in the outbound column.
• Outbound Addresses Including Subrealms - the number of outbound addresses in the realm
and all of its descendants.
• Outbound Streams This Realm Only - the number of outbound streams in the realm. The
criteria and counting rules for outbound streams are similar to those for outbound addresses.
• Outbound Streams Including Subrealms - the number of outbound streams in the realm and
all of its descendants.
If the Archiving add-on is installed, the following columns are present:
• Archiving Streams This Realm Only - the number of streams in the realm that have archiving
enabled.
• Archiving Streams Including Subrealms - the number of streams in the realm and its descendants that have archiving enabled. This item is formatted as a list of count/retention pairs. For
example, if a realm and its descendants have 45 streams archiving for 12 months, 201 archiving
for 24 months and 16 archiving for 36 months, then the output will be:
45/12, 201/24, 16/36
• Archive Retention Months - the number of months for which archived mail is retained. This
can be set on a realm-by-realm basis.
If the Secure Messaging add-on is installed, the following columns are present:
• Secure Messaging Streams This Realm Only - the number of streams in the realm that have
secure messaging enabled.
• Secure Messaging Streams Including Subrealms - the number of streams in the realm and its
descendants that have secure messaging enabled.
6.16.1
Computer-Readable Provisioning Information
To download the provisioning data in CSV format (suitable for importing into a spreadsheet), click
the Download in CSV Format link at the bottom of the page.
To download the data as JSON (suitable for processing by many scripting languages), click the Download in JSON Format link at the bottom of the page.
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Chapter 7
External Authentication
7.1
Introduction
In addition to its built-in user list, CanIt-Domain-PRO can authenticate users using external mechanisms. To enable the use of external authentication mechanisms, these basic steps must be followed:
1. A User Lookup must be defined. A User Lookup describes to CanIt-Domain-PRO how to look
up user information from an external source.
2. An Authentication Mapping must be created. An Authentication Mapping tells CanIt-DomainPRO which User Lookup to use for a given domain. You can use different authentication mechanisms for different domains, which gives CanIt-Domain-PRO considerable flexibility.
Some User Lookups can also perform streaming. That is, given an email address, they can return
the name of the stream associated with that email address. The LDAP (Section 7.2.2) and Program
(Section 7.2.3) User Lookups can perform streaming. Using a User Lookup to perform streaming is
very powerful; for example, you could use an LDAP lookup to stream all of a user’s aliases into his
single stream.
7.2
User Lookups
To create a User Lookup:
• Click on Setup and then User Lookups. You will see the User Lookup list:
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CHAPTER 7. EXTERNAL AUTHENTICATION
Figure 7.1: User Lookup List
• Click on Add a New User Lookup, and the User Lookup Wizard appears:
Figure 7.2: User Lookup Wizard
• Pick a name for the User Lookup, and click Next. The User Lookup method selection screen
appears:
Figure 7.3: User Lookup: Method Selection
• Enter a comment for the lookup method. The comment can be anything you like; its purpose is
to document the method so you remember what it does.
7.2. USER LOOKUPS
139
• Select a lookup method. CanIt-Domain-PRO supports the following methods:
– POP3: CanIt-Domain-PRO authenticates users against a POP3 server.
– IMAP: CanIt-Domain-PRO authenticates users against an IMAP server.
– LDAP: CanIt-Domain-PRO authenticates users against an LDAP server. If you are creating a new user lookup, then the LDAP choice is broken into four possibilities. The first
two are appropriate if you are authenticating against Active Directory and the last two are
appropriate if you are authenticating against a generic UNIX LDAP server:
1. LDAP (Active Directory: Log in using Windows username @ domain): This choice
pre-fills settings that are suitable for logging in using your Windows user-name or
Windows user-name followed by @ and the domain name.
2. LDAP (Active Directory: Log in using email address): This choice pre-fills settings
that are suitable for logging in with your email address.
3. LDAP (Generic: Log in using username @ domain): This choice pre-fills settings that
are suitable for logging in with your user-id (or user-id followed by @ and domain
name.)
4. LDAP (Generic: Log in using email address): This choice pre-fills settings that are
suitable for logging in with your email address.
Note:
Once an LDAP user lookup is created, editing it shows the method as simply LDAP. The
four possibilities enumerated above are simply conveniences that pre-select appropriate
settings when you first create the user lookup.
– Program: CanIt-Domain-PRO invokes a program (that you supply) to perform authentication.
– Program (Legacy method): CanIt-Domain-PRO invokes external programs in the same
way as older versions did (using the “Alternate Authentication” global setting that has
since been removed.)
– Rewrite: This method cannot be used for authentication; it can only be used for stream
mapping. It generates a stream name using simple rewriting rules on the email address.
• Normally, User Lookups may only be used by domains within the realm in which the User
Lookup is defined. However, if you set “Allow subrealms to use this User Lookup?” to Yes,
then domains in subrealms will be able to use the User Lookup. This is useful, for example,
if you have a number of customer realms that are all back-ended on the same LDAP or IMAP
server.
• Click Next.
7.2.1
IMAP and POP3 Authentication
If you selected IMAP or POP3 authentication methods, then the wizard looks like this:
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Figure 7.4: IMAP/POP3 User Lookup
To complete the setup:
• Enter the IP address or fully-qualified host name of the IMAP or POP3 server. If the server is
listening on a non-standard port, add a slash followed by the port number to the server name.
For example, if you have an IMAP server listening on port 1143 on the host magnesium, you
could enter magnesium/1143 as the server.
• If you would like to strip the domain name from the login name before attempting authentication, set the “Strip domain name” setting to Yes. If someone logs in to CanIt-DomainPRO as [email protected] and this setting is Yes, then the username passed to the IMAP
or POP3 server is simply user. (The default home stream, however, is normally the full
[email protected].)
• If you would like to strip the domain name from the home stream, set “Strip domain name
from home stream after authentication?” to Yes. This means that if someone logs in as
[email protected], her home stream will be user.
• If you would like CanIt-Domain-PRO to force user-names authenticated by POP3 or IMAP to
lower-case, set “Force user name to lower-case” to Yes. (This also implicitly sets the home
stream name on login to lower-case.) The user name is lower-cased before being presented to
the POP3 or IMAP server.
• If you would like CanIt-Domain-PRO to force stream names (as determined by the POP3 or
IMAP username) to lower-case, set “Force stream name to lower-case?” to Yes. If you want to
preserve mixed-case stream names, set this setting to No (which is the default.)
• If you want CanIt-Domain-PRO to validate the SSL certificate of the server (assuming SSL or
TLS is used), set “Validate server certificate” to Yes.
• Pick the appropriate encryption settings for CanIt-Domain-PRO to use when communicating
with the POP3 or IMAP server.
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141
• By default, when a user successfully logs in via POP3 or IMAP, CanIt-Domain-PRO caches the
username and encrypted password for 5 days. If your POP3 or IMAP server ever goes down,
this permits users to continue to log in to CanIt-Domain-PRO (provided they have logged in
successfully within the past 5 days.) You can change the cache time by editing “Number of
days to cache successful credentials”. If you set this parameter to zero, then CanIt-DomainPRO will not cache credentials upon successful login.
• By default, a user logging in as [email protected] is put into the stream
[email protected]. If you wish to rewrite the stream using a more sophisticated mechanism than simply stripping the domain, enter a rewrite expression for “Rewrite expression to
transform login name to stream name:” (Rewrite expressions are described in Section 7.2.6.)
For example, suppose example.org and example.net are aliases. You want users to log
in as either [email protected] or [email protected], but always want the stream to
be [email protected]. In this case, use a Rewrite Expression of %[email protected].
• Click Next to see a summmary of your settings.
• If all of the settings are correct, click Finish to create the POP3 or IMAP User Lookup.
7.2.2
LDAP Authentication and Streaming
If you are creating a new user lookup, then the LDAP choice is broken into four possibilities. The first
two are appropriate if you are authenticating against Active Directory and the last two are appropriate
if you are authenticating against a generic UNIX LDAP server:
1. LDAP (Active Directory: Log in using Windows username @ domain): This choice pre-fills
settings that are suitable for logging in using your Windows user-name or Windows user-name
followed by @ and the domain name.
2. LDAP (Active Directory: Log in using email address): This choice pre-fills settings that are
suitable for logging in with your email address.
3. LDAP (Generic: Log in using username @ domain): This choice pre-fills settings that are
suitable for logging in with your user-id (or user-id followed by @ and domain name.)
4. LDAP (Generic: Log in using email address): This choice pre-fills settings that are suitable for
logging in with your email address.
Note:
Once an LDAP user lookup is created, editing it shows the method as simply LDAP. The four possibilities enumerated above are simply conveniences that pre-select appropriate settings when you first
create the user lookup.
LDAP user lookups can be used for one or both of user authentication and stream mapping. When used
for stream mapping, the LDAP lookup method will also validate incoming email addresses against the
LDAP server, allowing rejection of invalid recipients immediately at the CanIt gateway.
Note:
In order for the LDAP User Lookup to validate incoming recipient addresses, it must be used for
streaming in Domain Mapping. Be sure to use another method of validation (e.g. Verification Servers
(see Section 5.4, Valid Recipients table) if you do not use your User Lookup for streaming.
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If you select one of the LDAP methods, you will see the LDAP User Lookup Wizard:
Figure 7.5: LDAP User Lookup
To complete the setup:
• In the “LDAP server(s)” box, enter the IP address or fully-qualified host name of your LDAP
server. You can enter a comma-separated list of servers if you have more than one LDAP
server. As with the IMAP and POP3 User Lookups, if a server listens on a non-standard port,
7.2. USER LOOKUPS
143
enter a slash followed by the port number after the server name. For example, if you have two
LDAP servers serverA and serverB, and the second listens on non-standard port 3389, enter
the following into the server box:
serverA, serverB/3389
If you want to use LDAPS (LDAP over SSL), enter the host name as an “ldaps” URL. For
example:
ldaps://server.example.com/
• Enter the Base DN of your LDAP tree in the “Base DN” box.
• Typically, CanIt-Domain-PRO needs to bind to the LDAP directory before it can search it.
Enter the Bind DN in the “Bind DN” box. If a password is required, enter it in the “Bind
password” box. Note that Active Directory does not support anonymous bind; a Bind DN and
Bind password are required.
• If you wish to use this User Lookup for authentication, set “Use this method for authentication?”
to Yes.
• If you would like to strip the domain name from the login name before attempting authentication, set the “Strip domain name” setting to Yes. If someone logs in to CanIt-Domain-PRO as
[email protected] and this setting is Yes, then the username passed to the LDAP server is
simply user.
• If you would like CanIt-Domain-PRO to force user-names authenticated by LDAP to lowercase, set “Force user name to lower-case” to Yes. (This also implicitly sets the home stream
name on login to lower-case.) The user name is lower-cased before being presented to the
LDAP server.
• Enter the search filter for login authentication. The string %s will be replaced by the user’s login
name. For most UNIX LDAP servers, a search filter of (uid=%s) is appropriate. For Active
Directory, it might be (sAMAccountName=%s).
• To use the Locked Addresses feature, CanIt-Domain-PRO needs to know the e-mail address of
a logged-in user. In most UNIX LDAP servers, this is stored in the mail attribute, while in
many Active Directory servers, this is stored in the attribute proxyAddresses. Enter the
appropriate value in “Attribute containing user’s e-mail address”.
• If you wish to control group membership using LDAP, enter the name of an LDAP attribute in
the “Attribute containing group names” box. This attribute should contain a comma-separated
list of group names. When a user authenticates, he/she will be considered to be a member of all
of the groups listed in this attribute.
• By default, when a user successfully logs in via LDAP, CanIt-Domain-PRO caches the username and encrypted password for 5 days. If your LDAP server ever goes down, this permits
users to continue to log in to CanIt-Domain-PRO (provided they have logged in successfully
within the past 5 days.) You can change the cache time by editing “Number of days to cache
successful credentials”. If you set this parameter to zero, then CanIt-Domain-PRO will not
cache credentials upon successful login.
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• If you wish to use the LDAP server to stream addresses as well as authenticate, set “Use this
method for streaming” to Yes.
• Enter the “Search filter for streaming”. For streaming, CanIt-Domain-PRO needs to look up
an e-mail address in the LDAP server. For most UNIX servers, the appropriate search filter is
(mail=%s), while for Active Directory, it is probably (proxyAddresses=smtp:%s). In
the search filter, the string %s is replaced with the e-mail address. %u is replaced with the local
part of the e-mail address (everything before ‘@’) and %d is replaced with the domain part of
the address (everything after the ‘@’.)
• If you would like CanIt-Domain-PRO to force stream names (as determined by the LDAP
lookup) to lower-case, set “Force stream name to lower-case?” to Yes. (This is the default.)
If you want to preserve mixed-case stream names, set this setting to No.
• CanIt-Domain-PRO needs to know which LDAP attribute contains the stream name. For most
UNIX servers, the appropriate attribute is uid, while for Active Directory, it is probably
sAMAccountName. You can use a comma-separated list of attribute names for the “List of
attributes to user for stream name” entry. CanIt-Domain-PRO will examine the attributes in
order and set the stream name to the first attribute found that exists and is non-blank. This is
useful if not all of your LDAP objects contain the same set of attributes, but they all contain at
least one attribute appropriate for use as the stream name.
• If CanIt-Domain-PRO successfully looks up an e-mail address, but the LDAP record lacks an
attribute for the stream name, CanIt-Domain-PRO can take one of the following actions:
– Tempfail the mail. We do not recommend this choice; it is available only for backwardcompatibility with earlier versions of CanIt-Domain-PRO.
– Place the mail in the default stream.
– Place the mail in a stream whose name is the same as the entire email address. This is
similar to AsIs address mapping. In this case, mail to [email protected] will go into
a stream called [email protected].
– Place the mail in a stream whose name is the user-part of the email address. This is similar
to ChopDomain address mapping. In this case, mail to [email protected] will go
into a stream called user.
– Place the mail in a stream whose name is the domain-part of the email address. This is
similar to ChopUser address mapping. In this case, mail to [email protected] will
go into a stream called example.org.
Set “Action if stream attribute missing” to the choice that is appropriate for your organization.
Note:
Recipient Validation (i.e. rejecting SMTP RCPT with ”User Unknown” when the address is not
found in LDAP) is only done if CanIt-Domain-PRO receives an actual response that there is no
corresponding LDAP record for the given e-mail address. Changes to this setting do not affect
validation.
Note:
If the LDAP lookup for an email address returns more than one stream (because multiple LDAP
entries match the address, for example), then CanIt-Domain-PRO picks a stream using the “AcCanIt-Domain-PRO — Roaring Penguin Software Inc.
7.2. USER LOOKUPS
145
tion if stream attribute missing” setting. It also raises an anomaly since this is usually a serious
error in the LDAP data; a given email address should be owned by one and only one stream.
• Normally, CanIt-Domain-PRO tries the LDAP servers in order. If you would like it to try them
in a random order (for load-balancing), set “Load-balance LDAP servers” to Yes.
• Some LDAP servers require CanIt-Domain-PRO to disconnect and reconnect and re-bind between queries. (Active Directory requires this.) If your LDAP server requires this, set the
“Reconnect for additional queries” setting to Yes.
• If you would like CanIt-Domain-PRO to cache stream lookups, set “Cache stream lookups in
database” to Yes.
• You can change the connect timeout from the default value of 120 seconds to any value from
2 to 120 seconds. This timeout only applies to streaming lookups by the Perl filters. It does
not apply to authentication, because PHP (used for the Web interface) does not have a way to
specify an LDAP connect timeout.
Once you have entered the LDAP parameters, click Next to review your entries, and Finish to create
the User Lookup.
7.2.3
Program Authentication and Streaming
With the Program User Lookup method, CanIt-Domain-PRO invokes an external program to authenticate users and map addresses to streams. If you select Program as your User Lookup type, the
Program User Lookup Wizard appears:
Figure 7.6: Program User Lookup
To configure the Program User Lookup:
• Enter the full path to your “account-info” script. This is an executable script or program that
you must supply. The path you supply must be an absolute path name. If you are running a
CanIt-Domain-PRO cluster, this script must exist (and be identical!) on all scanning servers and
the Web server.
146
• If you would like to strip the domain name from the login name before attempting authentication, set the “Strip domain name” setting to Yes. If someone logs in to CanIt-Domain-PRO
as [email protected] and this setting is Yes, then the username passed to the program is
simply user. The home stream, however, is normally [email protected].
• If you would like to strip the domain name from the home stream, set “Strip domain name
from home stream after authentication?” to Yes. This means that if someone logs in as
[email protected], her home stream will be user.
• If you would like to cache stream lookups, set “Cache stream lookups in database?” to Yes. We
strongly recommend enabling caching.
How the Program User Lookup is Invoked
• For authentication, the program is invoked as follows:
/path/to/script --authenticate
The program is then expected to read two lines from its standard input: The first line is a login
name, and the second line is a password. The program must then validate the login name and
password, and exit with one of the following exit codes:
– 0 — Authentication was successful.
– 1 — Authentication failed.
• For obtaining user information, the program is invoked as follows:
/path/to/script --info username
Here, the program is passed the successfully logged-on user name as a command-line argument.
It should print a series of key=value lines to its standard output, and exit with an exit status of
0. (The script doesn’t have to produce any output, but it can produce output if you want to pass
extra information to CanIt-Domain-PRO.)
The key/value pairs currently used by CanIt-Domain-PRO are:
– home stream=stream-name — sets the user’s home stream to stream-name instead
of his or her login name. One possible use could be to convert a login name to all lowercase on systems that permit case-insensitive authentication. This ensures that no matter
how the person logs in, she is directed to the correct stream name.
– groups=group1,group2,...,groupN — when the user logs in, add her to all of
the groups listed in the comma-separated list.
– mail=email-address — set the user’s e-mail address to email-address.
• For mapping an e-mail address to a stream, the program is invoked as follows:
/path/to/script --info-email address
Here, address is an e-mail address that must be streamed. The script should write key=value
lines to its standard output, and exit with one of the following exit codes:
7.2. USER LOOKUPS
147
– 0 — the address exists and was successfully streamed.
– 1 — there was a temporary failure streaming the address. The mail will be tempfailed.
– 67 — the address is not valid. CanIt-Domain-PRO will fail the SMTP RCPT command
with a “User unknown” failure code.
If the address was streamed successfully, the script must print the following line to standard
output:
stream=stream-name
This causes address to be mapped to stream-name. If no stream=stream-name line is
emitted, but the script exits with a zero status, then CanIt-Domain-PRO falls back to database
lookups, as described in Section 2.5 on page 34.
Sample Program for the Program User Lookup Method
The following is a very simple Bourne shell script illustrating how the Program User Lookup method
works. Real scripts would obviously be more complex and probably written in a more appropriate
language like Perl.
148
#!/bin/sh
do_auth () {
read user
read pass
# In reality, we would do a directory lookup against LDAP or similar
if test "$user" = "foo" -a "$pass" = "bar" ; then
exit 0
fi
exit 1
}
do_info () {
user="$1"
if test "$user" = "foo" ; then
echo "home_stream=foobar";
echo "[email protected]";
fi
exit 0
}
do_info_email () {
email="$1"
if test "$email" = "[email protected]" ; then
echo "stream=foobar-stream";
fi
if test "$email" = "[email protected]" ; then
# No such user
exit 67
fi
exit 0
}
# Main program
case "$1" in
--authenticate)
do_auth
;;
--info)
do_info "$2"
;;
--info-email)
do_info_email "$2"
;;
)
*
exit 1;
;;
esac
7.2. USER LOOKUPS
7.2.4
149
Program Authentication (Legacy Method)
If you select this User Lookup method, then CanIt-Domain-PRO falls back to behavior compatible
with previous versions. (This behavior is deprecated, however. New installations should use Program
Authentication as described in Section 7.2.3.)
• If a program called /usr/share/canit/scripts/account-info exists and is executable, CanIt-Domain-PRO invokes it as if it were the script supplied for a Program User
Lookup method.
• Otherwise, CanIt-Domain-PRO invokes /usr/share/canit/scripts/authenticate-user
to authenticate users and /usr/share/canit/scripts/address-to-stream to
convert an e-mail address to a stream. These scripts have been in use since CanIt-Domain-PRO
2.0 and are deprecated; you should convert to the new Program User Lookup method.
7.2.5
The account-info Script
Some User Lookup methods (such as POP3 or IMAP) as well as a lookup in the built-in user database
are not capable of passing extra information back to CanIt-Domain-PRO. For that reason, if any User
Lookup method other than Program or LDAP is used, CanIt-Domain-PRO still attempts to execute:
/usr/share/canit/scripts/account-info --info username
to obtain extra attributes (mail, groups and home stream) after a user logs in. If you need to set
users’ e-mail addresses or home streams, but have them authenticate against an IMAP or POP3 server,
simply supply an appropriate account-info script.
7.2.6
The Rewrite User Lookup
The rewrite user lookup is not used for authentication. It is only used to convert an address to a stream.
It does so by rewriting the email address using a rewrite expression.
To create a Rewrite User Lookup, enter the rewrite expression. CanIt-Domain-PRO rewrites an address as follows:
• The sequence %u in the rewrite expression is replaced with the local part of the email address
(that is, everything before the @ sign.)
• The sequence %d in the rewrite expression is replaced with the domain part of the email address
(that is, everything after the @ sign.)
• The sequence %s in the rewrite expression is replaced with the entire email address.
• Any other characters in the rewrite expression are copied as-is.
As an example of how you’d use the rewrite user lookup, consider an organization that owns
the domains example.com, example.org and example.net. It wants any email address
150
user@example.* to be placed in the stream [email protected]. That is, no matter what
the domain on the incoming email address, it shoul be replaced with example.com.
This can be accomplished by creating a rewrite user lookup with a rewrite expression of:
%[email protected]
and then using that user lookup as the Domain Mapping entry (Section 5.14) for all of the domains
example.com, example.net and example.org
Finally, observe that the Rewrite User Lookup can implement AsIs, ChopDomain and ChopUser
streaming (Section 5.14). The relevant rewrite expressions are:
• AsIs: %u@%d
• ChopDomain: %u
• ChopUser: %d
7.3
Authentication Mappings
Once you have set up your User Lookup methods, you need to tell CanIt-Domain-PRO which method
to invoke for each domain. To do this, click on Setup and then Authentication Mappings. The
Authentication Mappings page appears:
Figure 7.7: Authentication Mappings
To create a new authentication mapping:
1. Enter the domain name in the Domain field. If you enter a single asterisk (“*”) in this field,
then it is used as the default authentication mapping if an exact match is not found.
2. Select the User Lookup from the Mapping field. If there are any User Lookup methods added
to ancestor realms of the current realm, they will appear as additional choices if they are marked
as being available for subrealms.
7.3. AUTHENTICATION MAPPINGS
151
3. Click on Submit Changes
In Figure 7.7, we see that anyone who logs in as [email protected] will be authenticated using the POP3-Sample User Lookup. Anyone logging in with a different domain (or no
domain at all—simply user) will be authenticated using the LDAP-Sample User Lookup.
Domain or Mapping columns contain that string.
152
Chapter 8
Bayesian Filtering
8.1
Introduction to Bayesian Filtering
Bayesian filtering is a statistical technique whereby CanIt-Domain-PRO assigns a spam probability
based on training from users. Bayesian filtering can greatly improve the accuracy of CanIt-DomainPRO, and makes it harder for spammers to evade filtering.
Please consult the CanIt-Domain-PRO User’s Guide for additional details on using Bayesian filtering.
This guide only contains information relevant when setting up and administering CanIt-Domain-PRO.
8.2
Unauthenticated Voting
Normally, to vote if a message is spam or not spam, a user must log in. You can configure CanItDomain-PRO to permit unauthenticated voting; this can make life easier for end-users who can just
click on a link without worrying about entering a user name and password.
Note:
Think carefully about permitting unauthenticated voting. If voting links ever escape your organization
(as part of a forwarded message, for example), and your CanIt-Domain-PRO Web interface is externally accessible, outsiders can cast votes. We strongly recommend permitting unauthenticated voting
only if access the the CanIt-Domain-PRO Web interface is controlled in some other way.
To permit unauthenticated voting:
• Under Preferences and Quarantine Settings, set Permit unauthenticated voting to Yes
You can permit unauthenticated voting on a stream-by-stream basis. If you permit it in the default
stream, then it will be permitted in all streams that inherit from default (and that don’t override the
setting.)
153
154
8.3
CHAPTER 8. BAYESIAN FILTERING
The Bayes Journal
Bayesian training can be slow because it involves many database updates. For that reason, when you
train a message, CanIt-Domain-PRO simply makes a note of the fact that the message is to be trained
in a special table called the Bayes Journal. Periodically, a CanIt-Domain-PRO daemon process goes
through the Bayes Journal and actually updates the Bayes data.
For this reason, if you train some messages, these results will not immediately appear in the Bayes
Settings page. The Bayes Journal is run every 10 minutes or so, so your training should appear within
10-15 minutes.
8.4
Site-Wide and Realm-Wide Bayes Training
Whenever someone hand-trains a message, the message is trained in the default stream of the realm
as well as the stream containing the message. Additionally, it is trained in the default stream of all
ancestor realms. For example, if the realm foo is a subrealm of base and the realm bar is a subrealm
of foo, then hand-training a message in the stream bar:quux also trains it in bar:default,
foo:default and base:default. You may wish to add some or all of these ancestor-realm
default streams to the list of streams from which Bayes training is inherited.
8.5
RPTN
RPTN stands for the Roaring Penguin Training Network, and is a mechanism whereby multiple CanIt
installations can share Bayes votes. RPTN contains two main parts:
1. In the reporting phase, CanIt-Domain-PRO installations send reports about whether or not mail
they have seen is spam. A report essentially consists of a list of tokens in the mail message and
a spam or not-spam flag, depending on how the incident was disposed of. The RPTN server
aggregates all of the reports it receives and builds a database of Bayesian statistics from the
reports.
2. In the download phase, a CanIt-Domain-PRO installation downloads the aggregated data and
installs it in its database. This data can subsequently be used for Bayesian analysis.
To set up RPTN, click on Setup and then Wizards. Choose the RPTN Setup Wizard. The wizard
leads you through the following steps:
1. You are asked if you would like to download Bayes data from RPTN.
2. If you answered Yes in Step 1, you are given an opportunity to limit when RPTN data is downloaded. Downloading RPTN data can place a fair amount of load on the server, so you should
limit RPTN downloads to off-peak hours. Be sure to leave at least a four-hour download window, because RPTN checks are made every two hours. If the download window is too short,
you may miss a download.
8.6. RULESET AND GEOLOCATION DATA UPDATES
155
3. You are asked if you would like to submit reports to RPTN.
4. If you answered Yes in steps 1 or 3, you are prompted for your download username and password. You cannot submit RPTN reports or download RPTN data unless you supply a valid
username and password.
5. Your settings are summarized, and you are prompted to click Finish to save the changes.
RPTN data are downloaded into a stream called @@RPTN. If you would like to use RPTN data in
Bayesian analyis, you must include @@RPTN in the stream setting “Inherit Bayes training history
from these streams”. If you want all streams to inherit Bayes data from @@RPTN, then set the “Inherit
Bayes training history from these streams” setting in the default stream in the base realm.
Note:
To download RPTN data, the CanIt-Domain-PRO server must be able to make outgoing HTTPS connections (over TCP port 443) to the machine server.rptn.ca. To submit RPTN reports, the
server must be able to make outgoing HTTPS connections to server.rptn.ca and also be permitted to send outgoing e-mail to [email protected]. If you have a firewall in front of the
CanIt-Domain-PRO server, please ensure that the firewall rules permit the RPTN traffic.
8.6
Ruleset and Geolocation Data Updates
In addition to downloading Bayes data, CanIt-Domain-PRO uses your RPTN credentials to download
two other sets of data:
• Updated rules that are pushed out from time-to-time by Roaring Penguin.
• Geolocation data that maps IP addresses to countries and cities. (The data are derived from
the GeoLite City data from MaxMind, which requires the following acknowledgement: This
product includes GeoLite data created by MaxMind, available from http://www.maxmind.com/)
The updated rulesets are simply SpamAssassin rules that Roaring Penguin publishes as required when
a new spam variant is detected. The geolocation data is used by the country rules as described in the
User’s Guide. CanIt-Domain-PRO also tokenizes the country, region, city and latitude/longitude of
the sending relay for use in the Bayes database.
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CHAPTER 8. BAYESIAN FILTERING
Chapter 9
Permissions
9.1
Introduction
In addition to the fairly coarse-grained settings described in Section 6.5.1, “User Privileges”, CanItDomain-PRO allows you to implement fine-grained control over access to various parts of the Webbased interface.
CanIt-Domain-PRO has two kinds of permissions:
1. Stream Permissions control access to CanIt-Domain-PRO features that affect the filtering of email. For example, the ability to whitelist or blacklist senders, create custom rules, and so on
are all Stream Permissions. Stream Permissions depend on both the user and the stream; a given
user may have different permissions in different streams.
2. User Permissions control access to various parts of the CanIt-Domain-PRO user-interface not
directly connected to filtering mail. For example, access the different GUI preferences and the
ability to do WHOIS lookups are all User Permissions.
CanIt-Domain-PRO can associate permissions with users and with groups. Any user can be a member
of zero or more groups. CanIt-Domain-PRO always grants a user the union of all his user-specific
permissions and all his group permissions. Adding a user to a group, therefore, can only ever grant
additional permissions. It cannot take away permissions.
9.2
Stream Permissions
Every stream has associated with it an ordered list of stream classes. When CanIt-Domain-PRO looks
up stream permissions, it first calculates the list of stream classes associated with a particular user and
stream. Here is how CanIt-Domain-PRO computes the list of stream classes:
1. The name of the stream always comes first. Thus, for example, if you are viewing a stream
called mystream, then the list of stream classes starts with mystream.
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CHAPTER 9. PERMISSIONS
2. If mystream happens to be your “home stream” (Section 4.6), then @@HOME is added to the
list of stream classes.
3. If you have write-access in mystream, then @@WRITABLE is added to the list of stream
classes.
4. If you have read-access in mystream, then @@READABLE is added to the list of stream classes.
5. Finally, the wildcard value * is added to the end of the list of stream classes.
When CanIt-Domain-PRO determines what permissions you have in a particular stream, it uses the
following procedure:
1. It looks for permissions granted in the actual stream name. If it finds any, it stops searching the
stream classes.
2. Otherwise, it checks the the stream classes and adds all permissions found to the set of granted
permissions.
9.3
Determining Permissions
To determine a particular user’s permissions, CanIt-Domain-PRO performs the following steps:
1. First, it gathers all permissions associated with the particular user’s login ID. (These permissions
are shown in Figures 9.3 and 9.4.)
2. Next, it adds all permissions granted to all the groups to which the user belongs.
3. If there was no entry in the permissions table for the particular user (that is, if Step 1 found no
entries), then CanIt-Domain-PRO performs the following steps:
(a) If the user has root privileges, then CanIt-Domain-PRO adds all permissions granted to
the pseudo-user *root* or *localroot* in the user’s realm.
(b) Next, CanIt-Domain-PRO adds all permissions granted to the wild-card user * in the user’s
realm.
4. If no entry was found for Step 3, then CanIt-Domain-PRO performs the following steps:
(a) If the user has root privileges, then CanIt-Domain-PRO adds all permissions granted to
the pseudo-user *root* in all parent realms up to base.
(b) Next, CanIt-Domain-PRO adds all permissions granted to the wild-card user * in all parent
realms up to base.
9.4. GRANTING PERMISSIONS
9.4
159
Granting Permissions
To grant or deny permissions, click on Administration and then Permissions. The Permissions Page
appears:
Figure 9.1: Permissions Page
User column contains that string.
If you want to edit permissions for groups rather than users, click on the Groups link:
Figure 9.2: Permissions Page
9.4.1
Granting Stream Permissions
To grant stream permissions, click on the Edit link in the Stream Permissions column. The Stream
Permissions page appears:
160
Figure 9.3: Stream Permissions Page
• To enable a stream permission in a particular stream or stream class, enable the checkbox in the
appropriate row and column.
• To enter the name of a stream or stream class, enter it into the text box in the Per-Stream
Permission row. Note that when you enter permissions for a new user, you must enter the
stream class in the text box, or your changes will be discarded.
• To delete all permissions for a particular stream or stream class, click the Delete link at the
bottom of the appropriate column.
• To view permissions only for one stream or stream class, click on the stream or stream class
name.
• To make your changes take effect, click Submit Changes.
The Stream Permissions are:
• Blacklist Senders – The user is permitted to blacklist senders.
• Whitelist Senders – The user is permitted to whitelist senders.
• Hold/Tag Senders – The user is permitted to add a hold rule for senders.
• Blacklist/Whitelist/Hold/Tag Domains – These permissions are similar to the Sender Action
permissions, but they apply to domain rules.
• Blacklist/Whitelist/Hold/Tag Networks – These permissions are similar to the Sender Action
permissions, but they apply to network rules.
• Reject/Accept/Hold/Tag MIME Types – These permissions are similar to the Sender Action
permissions, but they apply to MIME type rules.
• Reject/Accept/Hold/Tag Filename Extensions – These permissions are similar to the Sender
Action permissions, but they apply to filename extension rules.
9.4. GRANTING PERMISSIONS
161
• Custom Rules – The user is permitted to create custom rules.
• SPF Rules – The user is permitted to create SPF rules.
• RBL Rules – The user is permitted to create RBL rules.
• Country Rules – The user is permitted to create country-code rules.
• Bayes Settings – The user is permitted to edit Bayes scoring rules.
• Blacklisted Recipients – The user can blacklist recipients.
• Valid Recipients – The user can enter recipients into the Valid Recipients Table.
• See Pending/Non-Spam/Spam Message – The user can see the specified message type in the
quarantine. Note that these permissions are normally off for @@READABLE streams; otherwise,
the user could see default’s spam quarantine.
• Add Alternate Addresses to Streams – The user can add aliases to his/her stream.
• Opt In/Out – The user can opt in or out of spam-scanning.
• Adjust Notification Settings – The user can adjust his or her notification settings.
• See Per-Stream/Global Reports – The user can see the specified reports.
• Quarantine Settings – Every quarantine setting has an associated permission. The user can
only see a quarantine setting if its corresponding permission has been granted. The user can
only change a quarantine setting if the permission has been granted and the user has writeaccess in the stream.
Note:
If a user does not have write-access in a stream, then permissions such as Custom Rules, Whitelist
Senders, etc. merely permit the user to see the rules. He or she still cannot change them.
9.4.2
Granting User Permissions
To grant user permissions, click on the Edit link in the User Permissions column. The User Permissions page appears:
162
Figure 9.4: User Permissions Page
The following User Permissions may be granted:
• Preferences – Unless this permission is granted, the user will not have access to the Preferences
menu or any of its sub-menus.
• WHOIS Lookups – If this permission is granted, the user will be allowed to do WHOIS
lookups.
• See Statistics – Allows the user to see the Reports : Statistics page.
• Use Log Searching – Allows the user to use the Log Searching feature (Chapter 17).
Note:
Users must have root privileges to use Log Searching; non-root users cannot use it even if Use
Log Searching is enabled. Also, the log-searching feature is available only on CanIt-DomainPRO appliances.
• See User’s Guide – Enables the link to the user’s guide.
• Use API – Allows the user to access the REST-based CanIt-Domain-PRO API. See the API
Guide for details.
• Provision Domains via API – Allows the user to provision new realms and domains via the
API. Note that a user must be a realm administrator and must have API access to be able to
provision domains. This option is available only on our CanIt-Domain-PRO appliances and
Hosted CanIt.
Note:
Allowing users to provision new realms and domains grants them tremendous power and may
be a security risk. Do not grant this permission except to highly-trusted realm administrators
• Use Expert Interface – Grants the user access to the expert interface.
• Create RSS Feed – Grants the user permission to create an RSS feed link for pending messages.
9.5. PERMISSION GRANTABILITY
163
• Turn off Stream Inheritance – Grants the user permission to completely isolate his stream by
disabling inheritance from the default stream. We do not recommend granting this permission
as a matter of course.
• Preferences – Each preference setting has an associated permission. A user can only change
those settings for which permission has been granted.
9.5
Permission Grantability
In CanIt-Domain-PRO, the System Administrator always has all permissions and can grant or deny all
permissions. However, the System Administrator can both limit the permissions available to Realm
Administrators (as described in Section 9.4) and limit which permissions Realm Administrators can
grant to themselves and other users.
To modify which permissions realm administrators can grant, click on Administration and then Permission Grantability. The Grantable Permissions page appears:
Figure 9.5: Permission Grantability
To delete an entry from the Permission Grantability table, check the Delete checkbox and click Submit
Changes.
To edit which permissions a user can grant, click on the Edit link in the appropriate table row. To add
a user to the table, enter the user ID in the User box and click Add. You can specify a realm in the
Realm pulldown; if you do not, then CanIt-Domain-PRO will determine the realm based on the user
ID.
Whether you add a new user or edit an existing user, CanIt-Domain-PRO brings up the Gantable
Permissions Detail page:
164
Figure 9.6: Grantable Permissions Detail
To allow a user to grant a permission, check the appropriate checbox. To prevent a user from granting a
permission, uncheck the checkbox. Click Submit Changes when you have set permission grantability
as you desire.
Note:
If you prevent a user from granting a permission, you should also turn off that permission for the user.
Otherwise, the user will lose the permission if he/she ever updates his permissions. For example, if a
realm administrator is permitted to blacklist senders, but not allowed to grant that permission, then if
she ever modifies her own permissions, she will lose the “Blacklist Sender” permission.
9.5.1
Grantability Algorithm
CanIt-Domain-PRO uses the following algorithm to determine which permissions a realm administrator can grant. For the sake of illustration, assume that the realm administrator’s user ID is
[email protected] and the realm name is myrealm.
1. First, CanIt-Domain-PRO looks for a grantability entry specifically for [email protected]
in the realm myrealm. If it finds such an entry, it uses it.
2. If Step 1 found no entry, CanIt-Domain-PRO looks for an entry for the user * in the realm
myrealm.
3. If Step 2 found no entry, CanIt-Domain-PRO looks for an entry for the user * in the realm
base.
4. If Step 3 found no entry, then the realm administrator is allowed to grant any permission.
Chapter 10
Streams, Inheritance and the Simple
GUI
10.1
Simplification
CanIt-Domain-PRO is extremely versatile, allowing end-users to set many parameters such as blacklists, whitelists, custom rules, and so on. For many users, this is intimidating—the users may be
unsophisticated, and just want to “make spam stop.”
CanIt-Domain-PRO allows the administrator to set up special streams with pre-configured settings.
Unsophisticated users then see a very simple interface which allows them to choose from one of these
settings. CanIt-Domain-PRO achieves this with stream inheritance and special streams.
Note:
Users who use the Simple GUI will not have their own quarantines. Special streams should be configured to pass, tag or reject. If any incidents are actually created, someone with administrative access
will need to check the special streams’ quarantines periodically.
10.2
Stream Inheritance
Streams in CanIt-Domain-PRO inherit rules and settings from other streams. By default, all streams
in a given realm inherit rules and settings from the default stream in that realm. The default
stream, in turn, inherits rules and settings from the default stream in the parent realm and so on all
the way up to the base realm.
If a stream stream1 inherits from another stream stream2, we refer to stream2 as the parent of
stream1. Conversely, we call stream1 the child of stream2.
Furthermore, suppose that stream2 inherits from stream3. We then call stream3 and stream2
the ancestors of stream1. These terms are illustrated in Figure 10.1:
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CHAPTER 10. STREAMS, INHERITANCE AND THE SIMPLE GUI
stream3
parent
stream2 inherits from stream3
child
stream2
parent
child
stream1
stream1
stream2
stream3
inherits from stream2
is the child of stream2
is the parent of stream1
and stream2 are the ancestors of stream1
stream1
Figure 10.1: Stream Inheritance Terminology
In addition to the default inheritance, streams can be configured to inherit rules and settings from
Special Streams (discussed next in Section 10.3.)
To determine a stream’s inheritance, CanIt-Domain-PRO consults the Stream Inheritance Table. To
see this table, click on Administration and then Inheritance:
Figure 10.2: Stream Inheritance Table
To determine a stream’s parent, CanIt-Domain-PRO first looks up the stream in the inheritance table.
If there is an entry, then that entry is used to determine the parent. If there was no entry, CanIt-DomainPRO looks up the key “*” in the inheritance table. If such an entry exists, it is used to determine the
parent.
In the example in Figure 10.2:
• user3 inherits from 01 Tag Only.
• user4 inherits from 00 Opt Out.
• user5 does not inerit from any other stream.
• user9 inherits from default.
10.3. SPECIAL STREAMS
167
• All other streams (except for default) inherit from 01 Tag Only, because of the wildcard
entry.
Stream or Inherits From columns contain that string.
10.3
Special Streams
A Special Stream is a normal stream with two extra behaviors:
• Other streams are allowed to inherit from special streams. Normally, a stream can only have
default as its parent. If you add special streams, however, other streams are allowed to make
the special streams their parents.
• If a stream inherits from a special stream, then mail for the child stream is held in the parent’s
quarantine. That is, by inheriting from a special stream, a stream “loses” its quarantine, giving
responsibility for any quarantined mail to the special stream.
10.3.1
Final Streams
A special stream may be marked final. If a special stream is marked final, then children of that stream
may not override the special stream’s rules or settings. If a stream inherits from a final special stream,
it’s as if the stream has given all control over to the special stream.
To see special streams, click on Administration and then Special Streams. The Special Stream Table
appears:
Figure 10.3: Special Stream Table
10.3.2
Creating Special Streams
To create a special stream, enter the name of the stream in the Stream text box, and a user-friendly
description in the Description box. Then click Add Special Stream.
168
In the example, the four streams 00 Opt Out, 10 Tag Only, 20 IT Staff and
30 Aggressive have been created. (Special streams are presented to end-users in order of
the stream name, so we named the streams beginning with numbers so they would sort from least
to most aggressive. We leave gaps between the stream numbers so we can insert more streams in
between if required.)
Once you have created the special streams, configure them appropriately. For example, for
00 Opt Out, you’d switch into that stream, and then under Preferences : Opt In/Out, you’d opt
that stream out. (For convenience, you can click on a stream name in the Special Stream Table to
switch into that stream.) For 30 Aggressive, you might change the stream settings to auto-discard
anything scoring 8 or more on the spam scale. For 20 IT Staff, you could have CanIt-DomainPRO hold suspect spam, and have a member of your IT staff check 20 IT Staff’s quarantine and
release false-positives.
Note that 00 Opt Out and 20 IT Staff are marked final. This means that rules and settings in
streams inheriting from these two special streams are ignored; only the special streams’ settings and
rules are used. On the other hand, streams inheriting from 10 Tag Only and 30 Aggressive may
define their own rules, settings, whitelists and blacklists.
You can define as many special streams with as many different settings as you deem appropriate. Note
that all special streams (by default) inherit from the default stream.
10.3.3
Deleting Special Streams
To delete a special stream, enable the checkbox in the Delete? column for the appropriate stream.
Then click Submit Changes. Warning: If you delete a special stream, then all inheritances from that
stream are deleted. Please see Section 10.2 for more details.
10.4
The Simplified GUI
If the CanIt-Domain-PRO administrator enabled the global setting G-4060 Users authenticated by
alternate means default to simple GUI? (Section 6.1), then such users only see the Simplified Interface:
Figure 10.4: Simplified Interface
10.5. INHERITANCE FROM NON-FINAL STREAMS
169
The simplified interface simply lists the possible Special Streams. The currently-inherited special
stream is highlighted in bold red print.
To inherit from a different stream, the user simply clicks on the appropriate radio button and clicks
Set Spam-Scanning Level. This adjusts the entry in the inheritance table.
To log out, the user clicks on Log Out.
If the user clicks on Enable Expert Interface, then he or she will have access to the usual CanItDomain-PRO interface. He or she can then turn off inheritance (via Preferences : Set Default
Stream) and take control over his or her own blacklists, whitelists, rules and spam quarantine.
Note:
If you have set the global setting G-4075 Switching to expert mode cancels stream inheritance
to Yes, then the act of clicking Enable Expert Interface cancels any inheritance that was in force,
making the stream inherit from default again.
To get back to the simple GUI, click on Simple Interface top-level menu entry. Note that this menu
entry does not appear until at least one special stream has been defined.
10.5
Inheritance from Non-Final Streams
If a stream inherits from a non-final stream, CanIt-Domain-PRO uses the following procedures to
resolve rules. In these examples, we assume that stream john inherits from the non-final stream
10 Tag Only
• For sender, domain and network blacklists and whitelists, and for MIME type and Filename
Extension rules, CanIt-Domain-PRO first looks for a rule associated with the original stream (in
our example, john.) If no such rule is found, it then tries the parent stream (in our example,
10 Tag Only) and then the parent of the parent, and so on up the inheritance chain.
• For custom rules, CanIt-Domain-PRO uses all the rules associated with the original stream in
addition to rules associated with the ancestor streams.
• Bayes data is associated with the original stream (john) and not the parent stream
(10 Tag Only).
10.6
Inheritance from Opted-Out Streams
If a stream or any of its ancestors is opted-out of spam-scanning, then no spam scanning is performed.
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Chapter 11
Periodic Reports
11.1
Introduction
CanIt-Domain-PRO can generate PDF reports about mail filtering activity and e-mail them to specified
recipients.
11.1.1
Periodic Reports
A periodic report has a name, a page size, a recipient and a recurrence. The name can be anything
you pick. The page size can be one of “US Letter” or “A4”. And the recipient can be any valid e-mail
address. The recurrence specifies how often the report should be generated and mailed out. Possible
choices for the recurrence are:
• On Demand — the report is never generated and mailed automatically, but only when specifically requested from the Web interface.
• Daily — the report is generated and mailed daily.
• Weekly — the report is generated and mailed weekly. You can choose the day of the week.
• Monthly — the report is generated and mailed monthly. You can choose either the first or
fifteenth day of the month.
11.1.2
Charts
A chart produces a single PDF page in a periodic report. It contains a chart corresponding to a
particular statistical query. A chart has a name (which can be anything you pick) and a type. The
available chart types are described below. Note that all charts accept parameters that modify the
results. For example, you can restrict the types of mail counted (you might only want to count spam,
for example), the destination domains, etc.
In addition to producing a page in the PDF report, each chart also generates a CSV file for importing
into spreadsheet software. (Some charts only produce CSV files and no PDF output; if this is the case,
it will be noted in the chart’s description.)
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CHAPTER 11. PERIODIC REPORTS
• Classification of Recent Mail. A pie chart showing the breakdown of recently-received email. (“Recent” e-mail is defined by Global Setting G-1550, “Number of hours to keep detailed
statistics”)
• Top Mail Countries. A pie chart showing the top countries sending recent e-mail.
• Top Domains. A pie chart showing the top recipient domains receiving recent e-mail.
• Top Mail Relays. A pie chart showing the top sending relays that have sent recent e-mail.
• Top Recipients. A pie chart showing the top recipient addresses receiving recent e-mail.
• Top Streams. A pie chart showing the top streams receiving recent e-mail.
• Top Viruses. A pie chart showing top recently-received viruses.
• Summary of Greylisting per Hour. A bar-chart showing how much recent e-mail was
greylisted and ungreylisted.
• Summary of Mail per Hour. A bar-chart showing the classification of recent e-mail per hour.
• Classification of Long-Term Mail. A pie chart showing the breakdown of received e-mail over
the long term. The timespan available in long-term statistics is determined by Global Setting
G-1500, “Expire statistics after this many days”.
• Top Domains (Long-Term Statistics). A pie chart showing the top recipient domains over the
long-term.
• Top Realms (Long-Term Statistics). A pie chart showing the top recipient realms over the
long-term.
• Top Streams (Long-Term Statistics). A pie chart showing the top recipient streams over the
long-term.
• Summary of Greylisting per Day. A bar chart showing how much mail was greylisted and
ungreylisted over the long-term.
• Summary of Mail per Day. A bar chart showing how daily classification of mail over the
long-term.
• Summary of Mail per Realm per Day. A bar chart showing daily mail volume per realm over
the long term.
• Number of Email Addresses Seen by Realm. A chart showing the number of addresses seen
in the last 30 days, broken down by realm. Note that this chart is only available as a CSV file; it
does not produce PDF output.
11.2. CREATING CHARTS
11.2
173
Creating Charts
The first step in creating a periodic report is to create one or more charts.
Click on Reports : Periodic Reports. The main Periodic Reports page appears:
Figure 11.1: Periodic Reports
To add a chart:
1. Click Add a New Chart.
2. Enter a name for your chart. This name will appear as the page title in the final reports.
3. Select a chart type.
4. Click Next...
Once you have selected a chart type, CanIt-Domain-PRO will display a page for setting parameters
for the chart. Set the parameters as appropriate for your chart and click Save Chart.
To edit an existing chart’s parameters, click on its name in the Name column.
To rename a chart, enter its new name in the Rename To... box and click Submit Changes.
To delete a chart, enable the corresponding checkbutton in the Delete... column and click Submit
Changes.
11.3
Creating Periodic Reports
Once you have created one or more charts, you can create periodic reports. To create a new periodic
report, click Add a New Report. The Add Periodic Report page appears:
174
Figure 11.2: Add Periodic Report
To create the report:
1. Pick a name for the report and enter it in the appropriate box.
2. Pick a time when the report should be sent. You can pick daily, weekly or monthly reports.
You can also select “On-Demand Only”. Such reports are never sent automatically, but are only
generated on demand.
3. Enter an e-mail address to which the report should be sent. You can enter multiple addresses by
separating them with commas.
4. Select a page size for the report (A4 or US Letter).
5. Pick one or more charts for the report by enabling the appropriate Add checkboxes.
6. Click one of the Submit Changes buttons.
11.4
Editing Periodic Reports
To edit an existing periodic report, click on the report’s name in the Name column. You alter the
reports parameters, add or remove charts, or move existing charts up or down from the report editing
page.
To delete a periodic report, enable the appropriate Delete... checkbox and click Submit Changes.
11.5. RUNNING A REPORT ON DEMAND
11.5
175
Running a Report on Demand
To run a specific periodic report on demand, enable the appropriate Run Now... checkbox and click
Submit Changes. The report will be queued for processing. Note that it can take anywhere from a
few minutes to a few hours for the report queue to be processed, so the report might take a while to be
mailed out.
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Chapter 12
Locked Addresses
12.1
Introduction to Locked Addresses
Locked Addresses are designed to solve the following problem: You want to give out your e-mail
address to someone, but you don’t trust that person or organization not to turn around and give or sell
it to others. You want an address that can only be used by the person or organization you give it to,
and not by anyone else.
CanIt-Domain-PRO has a complete solution to this problem. However, it does require some administrative overhead before users can take advantage of the feature.
12.2
Preparing to use Locked Addresses
Before end-users can use locked addresses, you need to perform the following steps.
12.2.1
Create a new domain
Choose a new domain, specifically for locked addresses. This domain should be a subdomain of your
“real” domain. For example, if you own the domain roaringpenguin.com, you might choose
to place all your locked addresses in la.roaringpenguin.com. The domain you use for locked
addresses should contain only locked addresses and should not be used for any “real” e-mail addresses.
12.2.2
Configure mail for the new domain
The next step is to configure the CanIt-Domain-PRO machine to receive mail for the new domain.
Obviously, the first thing you need to do is publish an MX record for the domain. For example, if your
locked address domain is la.roaringpenguin.com and your CanIt-Domain-PRO server’s name
is canit.roaringpenguin.com, you might add a DNS record that looks like this:
la.roaringpenguin.com.
1d
IN
MX
1 canit.roaringpenguin.com.
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CHAPTER 12. LOCKED ADDRESSES
Also, you need to configure the CanIt-Domain-PRO machine to accept and discard all mail for the
locked domain. (Mail should never be delivered to addresses in the locked domain, but just in case,
there should be a mechanism to discard them.)
Configuring Sendmail to accept mail for the locked domain is easy: Just add an entry in the access
database. In our example, it would be:
To:la.roaringpenguin.com
RELAY
(If you are running a CanIt-Domain-PRO Appliance, you can use Domain Routing from the Web
interface instead of manually editing Sendmail configuration files.)
The easiest way to configure Sendmail to discard mail for the locked domain is to make use of the
virtusertable feature. Add an entry like this in virtusertable:
@la.roaringpenguin.com
[email protected]
and ensure that mail to [email protected] gets discarded (by making an
alias from devnull to /dev/null.)
Of course, you need to substitute your own locked address domain for la.roaringpenguin.com
and your own CanIt-Domain-PRO server name for canit.roaringpenguin.com.)
12.2.3
Inform CanIt-Domain-PRO about the locked address domain
CanIt-Domain-PRO needs to know the domain you’re using for locked addresses, so it can treat any
such addresses specially. In the Web interface, click on Administration : Global Settings and enter
the locked address domain into the global setting G-10000 “Domain for Locked Addresses”
12.2.4
Associate each login name with an e-mail address
CanIt-Domain-PRO can only generate locked addresses if it has a real e-mail address for each loggedin user. For users in CanIt-Domain-PRO’s built-in user table (Section 6.5 on page 116), simply ensure
that you enter an e-mail address for each user.
For users authenticated via external means, the User Lookup method must return the user’s e-mail
address upon login. For some User Lookup methods such as POP3 or IMAP that cannot return the
e-mail address, you need to create an account-info script (Section 7.2.4 on page 149) and ensure
that a mail=email-address attribute is always emitted for each login that should be permitted to
use locked addresses.
Once all of these steps in Sections 12.2.1 through 12.2.4 have been performed, the Locked Address
feature is ready to use. Please consult the CanIt-Domain-PRO User’s Guide for details about how to
use a Locked Address.
Chapter 13
Attachment Handling
CanIt-Domain-PRO can handle file attachments in a number of different ways. Messages can be
delayed, rejected or held based on the attachment’s type. They can be scanned for viruses and held
or rejected using one or more configured virus scanners. If desired, attachments can also be removed
from the message and discarded, or held for access via a web-based system.
13.1
General Filename and MIME Type Rules
Whole messages can be rejected or held on a per-stream basis using the Filename Extensions or
MIME Types rules. See the section entitled Blacklists, Whitelists and Rules in the CanIt-DomainPRO Users Guide for full details.
13.2
Delaying Attachments
On a realm-wide basis, it is sometimes useful to delay certain attachment types temporarily, without
placing them in a stream’s quarantine. By delaying these attachments for a short period of time, you
can give your virus scanners and RBLs time to catch up with new virus and spam content.
13.2.1
Note:
Enabling the Feature
First, the feature must be enabled via the Web GUI. Log in as an admin user, and enable Delay
Attachments on the Setup : Features page.
Next, configure the time delay, by modifying Time in hours to delay messages with Delayed Attachments under Global Settings.
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13.2.2
CHAPTER 13. ATTACHMENT HANDLING
Creating Delay Rules
To create a delay rule, click on Administration and then Delayed Attachments. The Delayed Attachments screen appears:
Figure 13.1: Delayed Attachments
To add a rule:
1. Enter a filename pattern in the Filename Pattern box. A filename pattern is normally interpreted as a filename extension. For example, exe will match a file with the extension .exe.
Note that the pattern should not contain a period. If a filename pattern begins with ˆ, then it
matches an entire filename. For example, the pattern ˆbad.exe matches (only) the filename
bad.exe.
2. Enter a comment in the Comment box. This will help you remember why you are delaying the
given filename pattern
3. Click Submit Changes to add the rule.
Note:
Attachment-delaying is global. It cannot be adjusted on a per-stream basis.
13.2.3
How It Works
As an administrator, you may configure any number of file extensions or full filenames to be delayed.
When a message arrives matching that filename or extension, it will be held in a special @@DELAYED
stream for the number of hours specified in the Time in hours to delay messages with Delayed
Attachments configuration.
Once that time has elapsed, the message is automatically released from the @@DELAYED quarantine,
proceeding through the CanIt-Domain-PRO filtering process where normal scanning will proceed as
if that mail had just arrived.
13.3. STRIPPING ATTACHMENTS
181
Should it be necessary for a message to be released from @@DELAYED early, the admin user (or other
user with appropriate permissions) may manually release it. Note, however, that a message released
from @@DELAYED may be re-quarantined in its normal stream because of spam-scoring rules. That is
because messages released from @@DELAYED are scanned by CanIt-Domain-PRO as if they had never
been seen before; CanIt-Domain-PRO does not correlate what it believes to be a brand new message
with anything in the @@DELAYED stream.
13.3
Stripping Attachments
In addition to delaying, holding or rejecting mail based on characteristics of attachments, CanItDomain-PRO can strip attachments out of messages before forwarding the message. You can configure CanIt-Domain-PRO to strip out attachments and store them for retrieval via the Web interface,
or simply to strip them out and discard them.
Attachment-stripping rules can be set per-stream, but only the realm administrator can create or
edit attachment-stripping rules; normal users cannot. In addition, all streams inherit default’s
attachment-stripping rules, even if the “Inherit rules from ’default’ stream” setting is set to No.
To create attachment-stripping rules:
1. Click on Rules and then Attachment Stripping. You see the Attachment Stripping Screen:
Figure 13.2: Attachment-Stripping Rules
2. Enter a filename pattern in the Filename Pattern box. This pattern is interpreted exactly as for
Delayed Attachments.
3. Enter a comment in the Comment box.
4. Choose an Action setting to determine how CanIt-Domain-PRO handles the filename pattern:
• Keep in Message indicates that CanIt-Domain-PRO should not strip the attachment out.
This setting can be used in a particular stream to override settings in default.
• Strip and Store on Server indicates that CanIt-Domain-PRO should remove the attachment and store it in the PostgreSQL database. CanIt-Domain-PRO will also add a message
indicating that the attachment was stripped, and provide a link whereby the message recipient can retrieve the attachment.
• Strip and Discard indicates that CanIt-Domain-PRO should remove and discard the attachment. CanIt-Domain-PRO will add a note to the message indicating that the attachment was discarded and cannot be retrieved.
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CHAPTER 13. ATTACHMENT HANDLING
5. If you chose Strip and Store on Server as the Action, then enabling the Require Approval?
checkbox will force administrators to approve the release of held attachments.
6. Click Submit Changes to create the rule.
13.3.1
Approving the Release of Stripped Attachments
If an attachment rule specifies Require Approval, then when an end-user clicks on the link to retrieve
the attachment, he or she will receive a notification stating that an administrator must approve the
release of the attachment, as well as a code to supply to the administrator. To approve the release of
an attachment:
1. Click on Rules : Attachment Stripping
2. Click on the Approve Attachment for Release link near the bottom of the page.
3. Enter the code supplied to you by the administrator.
4. Preview the attachment if necessary.
5. Click on Approve for Retrieval if you wish to allow the end-user to download the attachment.
Chapter 14
URL Proxying
CanIt-Domain-PRO’s URL Proxying feature can help mitigate phishing attacks that trick users into
visiting hostile web sites and entering sensitive information. It does this by rewriting URLs in message
bodies to go to a proxy page that warns users not to enter sensitive information. Users can then click
on a link in the proxy page to visit the original URL. We call the rewriting of the link redirecting the
link.
Here is a screenshot showing what happens when a user clicks on a redirected link:
Figure 14.1: Redirected Link
In Figure 14.1,
the original sender sent an email containing the link
http://www.cnn.com/WORLD/?hpt=sitenav. CanIt-Domain-PRO redirected the link
to its proxy page. The proxy page shows the user the original link, the server hostname, and (if it can
be determined) the approximate location of the server. It also displays a warning not to enter sensitive
information. This can help to educate users about the legitimacy of the site and to remind them not to
enter sensitive information.
To continue to the original site, the user merely needs to click on “I understand and wish to follow the
link.”
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CHAPTER 14. URL PROXYING
14.1
Configuring URL Proxying
By default, CanIt-Domain-PRO proxies only URLs on the Known Phishing URLs list (Section 6.4.2).
To enable URL proxying for other URLs, you need to create URL proxying rules.
There are two basic strategies for using the URL proxying feature:
1. Enter a list of safe domains that should not be redirected, and have CanIt-Domain-PRO redirect
everything else. This is the safest approach, but can be annoying as most URLs end up getting
redirected.
2. Enter a list of questionable domains that should be redirected, and do not redirect anything else.
If you have a list of commonly-abused domains such as free form-creation sites, this can be a
viable method of cutting down on phishing while keeping the annoyance factor to a minimum.
To create URL proxying rules, click on Rules and then URL Proxy. The URL Proxy Rules page
appears:
Figure 14.2: URL Proxy Rules
• To enable URL proxying, set “Enable URL Proxy?” to Yes. This is a normal stream setting, so
if you set it in the default stream, it is inherited by other streams in the current realm and all
subrealms.
Scanning messages for URLs and replacing them may be expensive, so if a stream does not
need URL proxying, it is best to leave the setting at No. If the setting is No, then any URL
Proxy Rules are ignored and the Known Phishing URLs list is not used.
• Set your default policy by entering a domain of * and either enabling or disabling the Redirect
checkbox. In Figure 14.2, we proxy URLs by default. The possible policies are:
14.2. PROXYING KNOWN PHISHING URLS
185
– No — do not proxy URLs within this domain.
– Yes — always proxy URLs within this domain.
– Only if tagged as spam — proxy URLs within this domain only if the email is tagged as
spam and the stream is in tag-only mode.
• Set policies for specific domains by entering them in the Domain box and enabling or disabling the Redirect checkbox. Note that a rule for a domain like example.com applies to
example.com and all subdomains unless there is a more specific rule.
URL proxy rules follow the normal stream inheritance. CanIt-Domain-PRO uses the first matching rule in the most-specific stream to determine whether or not to proxy a URL.
• You can delete a URL Proxy Rule by enabling the appropriate checkbox in the Delete? column.
• Click Submit Changes to apply your changes.
14.2
Proxying Known Phishing URLs
CanIt-Domain-PRO maintains an updated list of URLs believed to have been used in a phishing attempt. If one of those URLs is encountered in a stream where URL proxying is enabled, the URL is
always proxied regardless of any domain rules. In addition, if a user clicks on the modified link, he or
she is not given an option to visit the original URL. Instead, CanIt-Domain-PRO displays a message
indicating that the original link led to a suspected phishing site.
14.2.1
Known Phishing Test Point
The nonexistent URL canit-url-proxy-testpoint.example.com may be
used to test the URL proxy.
If you send yourself an email containing the text
http://canit-url-proxy-testpoint.example.com, then CanIt-Domain-PRO should
treat it as a known phishing URL.
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CHAPTER 14. URL PROXYING
Chapter 15
SMTP Server Testing
CanIt-Domain-PRO permits you to run a test SMTP session against a back-end SMTP server. It
displays the complete SMTP session and this lets you diagnose problems that may exist.
15.1
An SMTP Primer
Internet email is delivered using a protocol called the Simple Mail Transfer Protocol, or SMTP. SMTP
runs over TCP, usually on port 25.
In an SMTP session, there are two computers involved. The machine attempting to send email is the
one that initiates the connection, and it is called the SMTP Client. The machine that is intended to
receive the email accepts an incoming connection from the client and is called the SMTP Server.
The data exchanged between an SMTP client and an SMTP server is human-readable plain text. It
consists of a number of client commands, each of which is responded to with a server reply. The only
exception is that immediately upon the client connecting to the server, the SMTP server issues a server
reply called the server banner, without waiting for a command from the client. The flow of an SMTP
session is shown in Figure 15.1:
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CHAPTER 15. SMTP SERVER TESTING
1. Client connects
SMTP Client
2. Server sends banner
SMTP Server
3. Client sends command
SMTP Client
4. Server sends reply
SMTP Server
5. Client sends command
SMTP Client
6. Server sends reply
SMTP Server
n−1. Client sends QUIT
SMTP Client
n. Server closes connection
SMTP Server
Figure 15.1: SMTP Session
Each server reply consists of a three-digit reply code followed by additional text. The first digit of the
reply code indicates the success or failure of the preceding client command; the first-digit responses
are as follows:
• 2 indicates a successful reply. It means that the preceding client command succeeded and the
server is waiting for the next command.
• 3 indicates a provisionally successful reply. It means that the preceding client command succeeded, but more information is needed before an overall success or failure status can be returned. This reply code is not frequently used and will not appear in CanIt-Domain-PRO’s
SMTP tester.
• 4 indicates a temporarily unsuccessful reply, often called a tempfail. It means that the preceding
client command failed, but that it may succeed at some point in the future if the client retries
the SMTP session. Examples of conditions that could elicit such a response are full disks or
problems reaching a directory server.
• 5 indicates a permanently unsuccessful reply, often called a permfail. It means that the preceding
client command failed and that there is no point in the client retrying later on because it is not
15.2. TESTING AN SMTP SERVER
189
likely to ever succeed. A condition that could elicit such a response is an attempt to send mail
to a nonexistent recipient.
15.2
Testing an SMTP Server
The SMTP server-testing feature can be accessed from three places in the Web interface:
• From the Test link next to each Verification Server entry.
• From the Test link next to each Domain Routing entry.
• From the Test links on the Domain Overview page.
When you access the SMTP server-testing feature, the SMTP Server Test Parameters page appears:
Figure 15.2: SMTP Server Test Parameters
To run the test, enter the following parameters:
• Enter the name of the domain to test in the domain name box. Note that this may already be
filled in for you.
• Provide the first part of a valid email address. For example, if you are testing the domain
example.com and you know that [email protected] is a valid email address, enter
info in the second box.
• Optionally enter the server name and IP in the next box. If you leave this box blank, the server
will be taken from the Verification Server or Domain Routing entry. Note: Only the site administrator can test arbitrary servers. Realm administrators can only test servers that are Verification
Server or Domain Routing entries.
• If a domain has both a Verification Server and a Domain Routing entry, select which server to
test. This choice appears only for domains that do in fact have both types of entries.
• Click Run the Test to test the SMTP server.
190
15.3
SMTP Test Results
Once you run a test, the Test Results page appears:
Figure 15.3: SMTP Server Test Results
The results are displayed in a three-column table. The columns are:
• Time (s) is the time in seconds that has elapsed since the initial SMTP connection was made.
• Source is the source of the message. It is one of Info, meaning an informational message
and not part of the SMTP session; Server, meaning a server reply, or Client, meaning a client
command.
• Message is the specific message, reply or command. The server reply codes are highlighted;
client commands are shown in bold.
15.3. SMTP TEST RESULTS
191
Let’s step through the SMTP session in Figure 15.3:
1. At time 0.0, CanIt-Domain-PRO successfully
vanadium.roaringpenguin.com.
connected
to
the
SMTP
server
2. At time 0.099, the server replied with a successful response code 220 and its banner.
3. Next
at
time
0.099,
the
EHLO colo3.roaringpenguin.com
client
sent
its
first
command:
4. At time 0.135, the server sent back a multi-line reply. Note that all but the last line have a dash
instead of a space after the reply code. The multi-line reply has reply code 250, indicating that
the EHLO command was successful.
5. Next at time 0.135, the client sent a MAIL From: command.
6. At time 0.167, the server responded to the MAIL From: command with a successful reply
code.
7. Next at time 0.167, CanIt-Domain-PRO informed us that it was going to attempt to send mail
to a valid email address.
8. And next at time 0.167, the client sent a RCPT To: command, specifying the email recipient.
9. At time 0.201, the server replied with the code 250, indicating that the preceding RCPT To:
command was successful.
10. Next at time 0.201, CanIt-Domain-PRO informed us that it was going to attempt to send mail
to a (likely) invalid address.
11. Finally at time 0.201, CanIt-Domain-PRO sent a RCPT To: command that specified a recipient that is very unlikely to exist.
12. At time 0.233, the server replied with the code 550, which indicates a permanent failure. The
preceding RCPT To: command failed and is not likely to succeed in future.
13. At time 0.234, the client sent a RSET command which throws away everything done so far in
the SMTP session.
14. At time 0.265, the server indicated the success of the RSET command.
15. Next at time 0.265, the client sent a QUIT command.
16. Finally, at time 0.296, the server acknowledged the success of the QUIT command and closed
the connection.
192
Chapter 16
CanIt Storage Manager
16.1
Storage Manager Concepts
Normally, CanIt-Domain-PRO stores all incident-related data in the PostgreSQL database. For many
sites, this works very well and there is no need for any alternate storage mechanisms. However, for
large sites, storing large amounts of text in the database can be very burdensome, leading to very large
databases and the consequent very long database dump and VACUUM processes.
To alleviate this problem,
CanIt-Domain-PRO ships with a program called
canit-storage-manager. This program allows you to store large textual data in the file
system rather than in the PostgreSQL database. The benefits of using the storage manager are:
1. The large amounts of text do not have to be dumped with each database backup, and they do not
have to be VACUUMed.
2. Because the data are stored as ordinary files, you can easily back up and synchronize the data
to other machines.
3. canit-storage-manager is optimized for the quick storage and retrieval of textual data,
so it reduces the burden on the database server.
4. canit-storage-manager can be run on a different machine from the database server,
which improves scalability.
193
194
CHAPTER 16. CANIT STORAGE MANAGER
16.1.1
Figure 16.1 illustrates how the storage manager works:
scanner
TCP traffic
TC
P
tra
ffi
c
ticker
TCP traffic
canit−storage−manager
Web UI
TC
Disk traffic
P
c
ffi
tra
File
System
scanner
Figure 16.1: CanIt Storage Manager
• The storage manager daemon runs on one machine and stores data locally on that machine’s file
system.
• The scanners, ticker and Web interface processes (running on the same machine or in general
on different machines) communicate with the storage manager daemon via a TCP connection.
• The scanners, ticker and Web interface make requests to fetch and store data and the storage
manager daemon carries out those requests.
• Old data are expired by the cron job. The storage manager daemon supports a special “purge”
request to delete old data.
16.2. CONFIGURING THE STORAGE MANAGER
16.2
195
Configuring the Storage Manager
Before configuring the storage manager, you need to make the following decisions:
• You need to pick one or more machines to run the storage manager. These machines should be
fast with plenty of memory and (most importantly) fast disks.
• You need to pick a directory under which the storage manager can store data. (It has to be the
same directory on each machine that runs storage manager.) Be sure there is sufficient disk
space for your expected mail storage! The required disk storage is given approximately by the
following formula. (Note that this is a worst-case estimate. It assumes that 100% of your mail
volume is spam and that every message is larger than 8kB and is held locally.)
S = (Dsig × M ×V ) + (Ddata × 8kB ×V ) + (Ddata × M ×V )
where:
– S is the required amount of disk space.
– V is the average number of messages received in a day.
– M is the average size of a message.
– Dsig is the number of days before you expire old Bayes signatures.
– Ddata is the number of days before you expire old data.
For example, if you receive 50,000 messages per day averaging 20kB per message, you retain
Bayes signatures for 3 days and you expire old data after 28 days, the required disk space is:
S = (3 × 20 × 50000) + (28 × 8 × 50000) + (28 × 20 × 50000) = 42200000kB or about 42GB.
16.2.1
Enabling the Storage Manager
Before using the storage manager, ensure that all machines in your CanIt-Domain-PRO cluster can
connect to the storage manager daemon on port 6568 (or whatever port you choose for it to listen on.)
16.2.2
The Configuration Wizard
Once you have decided on the machine and directory, you can begin configuring the storage manager
from the Web interface. Click on Setup and then Storage Manager Wizard.
1. First, you are asked whether or not you wish to use the storage manager. Answer Yes. Then
click Next. The storage manager configuration page appears:
196
Figure 16.2: Storage Manager Configuration
2. Enter the following information into the wizard:
(a) For each host in your cluster, select whether you want the host to run storage manager in
Read/Write mode, Read-Only mode, or not at all. (Normally, you should never run storage
manager in Read-Only mode; this mode is intended only when you are retiring a storage
manager node and want to leave it in the pool until all data on it expires.)
Note:
If you change a Storage Manager node from Read/Write to Read-Only or vice-versa, you
must run /etc/init.d/canit-system restart-gracefully on that node after finishing the Storage Manager wizard. Otherwise, the change will not be picked up by
the Storage Manager daemon.
(b) If you have more than one host running a storage manager deamon and you want CanItDomain-PRO to store data only on some subset of them, enter the number of hosts on
which to attempt writes in the “Number of Copies to Write” box.
(c) If CanIt-Domain-PRO is writing more than one copy of the data and you want it to continue
operating even if some writes fail, enter the number of writes required to succeed in the
“Success Threshold” box.
(d) Enter the port on which the storage manager daemon should listen. The default port is
6568. (The port must be the same for all storage manager hosts.)
(e) If you want to restrict the daemon to listen on a particular IP address, enter it. Normally,
you should leave this field blank. If you are running storage manager on more than one
host, you must leave this field blank.
Once you have entered the settings, click Next.
3. Review the settings and then click Finish.
16.2. CONFIGURING THE STORAGE MANAGER
16.2.3
197
Local Configuration
On each host, a number of settings in the [storagemanager] section of /usr/share/canit/
canit.conf control various aspects of the storage manager. If you want to change the settings,
create a [storagemanager] section in /etc/mail/canit/canit.conf; do not edit /usr/
share/canit/canit.conf directly. The settings are:
pidfile (string) A file used by the Storage Manager server to write its process ID and
to lock against concurrent Storage Managers.
The default value is /var/run/
canit-storage-manager.pid.
rootdir (string) The root directory under which data are stored. The default value is /var/lib/
canit-storage-manager.
user (string) The UNIX user as which the Storage Manager server should run. The default value is
defang.
client retry delay (integer) specifies the delay in reconnecting to a dead storage manager node. If
a CanIt-Domain-PRO cluster node fails to connect to a storage manager node, it will not retry
the connection for client retry delay seconds. This can help prevent a dead storage
manager node from bogging down the clients in blocked connect calls.
client connect timeout (integer) specifies the timeout in seconds for a connection attempt to a Storage Manager node. The default is 5 seconds.
client operation timeout (integer) specifies the timeout in seconds for a read or write operation to a
Storage Manager node once connection has been established. The default is 20 seconds.
order (string) specifies the order in which to try Storage Manager nodes. The default is “auto”,
in which case CanIt-Domain-PRO periodically measures the latency to each Storage Manager
node and accesses them in order of increasing latency (fastest to slowest). If you want to specify
a particular order, set the value to a space-separated list of fully-qualified host names. The hosts
will be tried in the order given. If you do not specify all the hosts, then any remaining hosts are
tried after the ones specified by the order parameter.
16.2.4
Starting the Storage Manager
Once the settings have been saved, you should log in to each host that will run the storage manager
daemon. Become root and start the storage manager daemon:
# /etc/init.d/canit-system check
(Your canit-system program may be located in /usr/share/canit/scripts/canit-system
instead.)
The canit-system startup script should run on bootup; it will start the Storage Manager if required.
198
16.2.5
Data Stored in the Storage Manager
Once the storage manager is enabled, CanIt-Domain-PRO stores the following data in it rather than in
the PostgreSQL database:
• Bayes signatures.
• Message previews (the first portion of an incident’s message).
• Entire messages (if the message is being held locally for some reason.)
In addition, CanIt-Domain-PRO uses the storage manager rather than the database for collecting statistics. These statistics are periodically summarized out of storage manager and the summaries are placed
in the database.
16.3
Backup Considerations
Once you start using the storage manager, the nightly database dump will not contain all of the information about incidents. In addition to backing up the nightly database dump, you should also back
up the entire storage manager directory tree. (This directory is specified in /etc/mail/canit/
canit.conf as the rootdir setting in the storagemanager section. If there is no rootdir
setting, then the default path is /var/lib/canit-storage-manager.)
The files in that directory are ordinary files; you can back them up with tar or rsync or your
favourite backup tool. However, there are many, many small files within many, many directories and
subdirectories. Test to confirm that your backup tool can handle the directory.
The best time to back up Storage Manager is after the nightly cron job has finished. This is because
(a) expired data will have just been purged; and (b) the system should be less busy, resulting in less
contention for disk I/O.
If you have more than one CanIt-Domain-PRO server (in other words, a cluster) then it is best to
run storage manager on multiple CanIt-Domain-PRO servers rather than using a backup tool. See
section 16.4.
16.4
Running multiple Storage Managers
If you have more than one CanIt-Domain-PRO server running in a cluster then we strongly recommend
running storage manager on at least two servers. There are several advantages:
• Storage Manager automatically load balances between its nodes;
• Multiple redundant copies of the data eliminate the need for backups;
• When migrating a server, you can skip the process of migrating storage manager as the other
nodes will carry the data.
16.5. PS OUTPUT
16.5
199
ps Output
If possible, canit-storage-manager changes the string shown by the ps command to reflect
what it is doing. For example, ps might show the following output:
canit-storage-manager: 10.0.0.1 scanner_6448 store bayes_sig 19819
The output above means that this instance of the storage manager is connected to the scanner with
process-ID 6448 on the machine 10.0.0.1. It is currently executing the command “store bayes sig
19819”.
200
Chapter 17
Searching Logs
17.1
Introduction
CanIt-Domain-PRO has the ability to index mail logs in the PostgreSQL database and search them.
This can be used to diagnose many mail problems such as missing messages, duplicate messages, etc.
Note:
The log-searching feature is available only on our Debian-based appliance build. It is not available
in the source or RPM versions of CanIt-Domain-PRO. See the CanIt-Domain-PRO Installation Guide
for details on installing the log-searcher.
In addition to presenting search results from the log files, CanIt-Domain-PRO also annotates the loglines to provide a clear explanation of what each line means. This can greatly ease troubleshooting.
17.2
Log Basics
CanIt-Domain-PRO uses the Sendmail program to transfer mail. It also uses the MIMEDefang filtering tool as the basis for its filtering. There are therefore three sources of log lines:
1. Sendmail.
2. The core MIMEDefang tool.
3. CanIt-Domain-PRO itself.
The log indexer groups log lines for a given message into a log document. A log document consists of
the set of log lines that describe the process of one message transmission through the CanIt-DomainPRO system.
The common element between different log lines that allows them to be grouped together is the Sendmail queue ID. This is an identifier assigned by Sendmail to each message transmission. A typical
queue ID might look like this: oBGIkIUj026238
201
202
CHAPTER 17. SEARCHING LOGS
17.3
Searching the Logs
There is a 30-minute delay between a log-line being created and the indexer indexing it. Therefore,
you can search for log lines starting as far back as your logs go up until 30 minutes before the current
time.
17.3.1
Note:
Performing a Search
Only the system administrator or realm administrators can use the log-searching facility. In addition,
the user must have permission to see quarantine contents.
To search the logs, click on Administration : Search Logs. The Log Search page appears:
Figure 17.1: Log Search Page
The Log Search page lets you build up a complex search query and then execute it. Here’s how
log-search queries work:
• Start date and End date restrict the time interval over which the search is performed. These
17.3. SEARCHING THE LOGS
203
are not actually part of the query.
• A query is a list of zero or more groups. Each group is evaluated as a unit before evaluating the
next group.
• Each group consists of one or more expressions. Each expression is evaluated as a unit.
• An expression consists of a field, a relation and some data. These will all be explained soon.
• Within a group, expressions are joined with AND, OR, AND NOT or OR NOT. The AND
operator is evaluated with higher precedence than OR. (If you include NOT, the NOT negates
the next expression.) Thus, for example, a query like:
(X = 1) AND (Y = 2) OR (A = 3) AND NOT (B = 4)
is evaluated as:
((X = 1) AND (Y = 2)) OR ((A = 3) AND (NOT (B = 4)))
• Within a query, groups are joined with AND, OR, AND NOT or OR NOT. Again, the AND
operators have higher precedence than OR.
17.3.2
Fields
The possible fields for searching logs are:
• Incident ID lets you search for a specific CanIt-Domain-PRO incident ID.
• Queue ID lets you search for a specific Sendmail Queue ID.
• Sender lets you specify an envelope sender’s email address.
• From: Header Address lets you specify the email address appearing in a message’s From:
header.
• List of Rules Hit lets you search the tests=xxx field of CanIt-Domain-PRO’s what= log
line. The most useful way to use this field is with the contains relation. If you use that
relation, you can search various rule types as follows:
– To search for a SpamAssassin rule such as HTML MESSAGE, enter the rule identifier exactly as shown.
– To search for a Compound Rule with ID N, search for: ;CN ( where the semicolon, the C
and the ( are literal.
– To search for a Custom Rule with ID N, search for: ;N ( where the semicolon and ( are
literal.
– To search for an SPF result of xxx, search for: SPF(xxx:
204
– To search for an DKIM result of xxx, search for: DKIM(xxx:
– To search for a DMARC
DMARC(DMARC POLICY xxx).
result
of
DMARC POLICY xxx,
search
for:
• Recipient lets you specify an envelope recipient’s email address.
• Source Relay IP lets you restrict results to messages relayed from a specific IP address.
• Destination Relay IP lets you restrict results to messages relayed to a specific IP address.
• Subject lets you specify the subject of a message.
• Message ID lets you specify a Message ID (found in the Message-Id: header of an email.)
• Reporting Host lets you restrict the search to messages processed by a particular host. Note
that you need to specify the host name as it appears in the log file.
• Classification lets you restrict messages based on their classification. Possible values for classification are:
– Accepted
– Rejected
– Discarded
– Greylisted
– Pending
– Tagged
– Streamed
• Stream lets you restrict results to messages within a given stream.
• Score restricts the results based on score.
• Reason restricts results to messages with the given reason=xyz entry in their logs.
• Detail restricts results to messages with the given detail=xyz entry in their logs. For more
information about the reason and detail fields, see Appendix H, “Logging”.
• Realm lets you restrict messages to a particular realm. The Realm field is displayed only if you
have access to more than one realm.
17.3.3
Creating a Log Search Query
To create a log search query:
• Starting with a blank query, select a field and relation for the search. Enter the data to search for
and click Add
17.4. SAVING LOG SEARCHES
205
• Continue to refine the query by selecting additional fields and relations and entering additional
data. Also, select one of AND, OR, AND NOT or OR NOT as the logical operator to join the
new expression to the existing query.
• Click Add to add the new expression to the current group, or click Add as New Group to start
a new group.
• Click Delete to delete the most recently-added expression if you made a mistake.
17.4
Saving Log Searches
CanIt-Domain-PRO permits you to save a log search and call it up later to redo the search.
To save a log search:
1. Create the log query in the normal manner.
2. Enter the name under which you would like to save the search in the box to the right of the Save
Search As... button.
3. Click Save Search As...
17.4.1
Managing Saved Log Searches
To manage saved log searches, click on Managed Saved Searches. The Saved Log Searches page
appears:
Figure 17.2: Saved Log Searches
To recall a saved log search, click on the name of the search. The log-search page will appear with the
query loaded from the saved search.
To add a comment to a saved log search, enter the comment in the appropriate box and click Submit
Changes.
To delete saved log searches, enable the appropriate checkboxes in the Delete? column and click
Submit Changes.
206
17.5
Log Search Results
After you click Add and Search to submit a log search request, CanIt-Domain-PRO returns a list of
matching results. This list might look something like Figure 17.3:
Figure 17.3: Log Search Results
Within the results page:
• Click on the small up- or down-arrows next to each column to sort by that column in ascending
or descending order. The current sort order is shown by the red arrow.
• Click on a Queue ID link to view the detailed log lines for that queue ID.
• If there is an incident associated with the logs, the message subject will be a link. Click on it to
see the Incident Details page.
Note:
Sometimes a group of log lines does not contain complete details about a message. In this case,
CanIt-Domain-PRO acts as follows:
• If the subject could not be determined, CanIt-Domain-PRO displays the subject as (Not
Logged).
• If the stream could not be determined, CanIt-Domain-PRO assumes the default stream.
• If the realm could not be determined, CanIt-Domain-PRO assumes the base realm.
It is important to remember that for queue retries and other fragmentary groups of logs, the subject,
realm and stream may not be able to be determined.
17.5.1
Detailed Results
If you click on a queue ID, the Detailed Results page appears:
17.5. LOG SEARCH RESULTS
207
Figure 17.4: Log Search Details
This shows each log line related to the message transmission. To see the timestamp in a more readable
format, hover the mouse cursor over the timestamp. For a detailed explanation of a log line, click on
the question-mark icon next to the line. You can expose details for all log lines by clicking Show All
Explanations.
Finally, if you need the raw log lines (for example, to send to someone for analysis), click on Show
Raw Logs.
17.5.2
Downloading Log Lines
At the bottom of the log results page, you will see one or two links:
• Bookmarkable Link is a link that you can copy and paste or send via email to redo the
currently-displayed log search.
• Download Logs is a link that permits you to download all logs that correspond to a particular
query. The downloaded logs are in plain-text format that can be opened with a text editor.
CanIt-Domain-PRO does not always provide a Download Logs link. If the number of log search
results is greater than the internally-configured MaxDownloadableLogs setting (default 100 log entries), then CanIt-Domain-PRO does not permit logs to be downloaded.
The CanIt-Domain-PRO site administrator can increase the limit by creating a file under the CanItDomain-PRO web tree called site/config.d/99 logentries.php with the following content:
<?php
global $Config;
$Config['MaxDownloadableLogs'] = 500;
?>
208
In the previous example, the limit was raised from 100 to 500.
When you download log lines, they are grouped by log host. Within a given log host, the lines are
sorted chronologically. To sort all lines chronologically regardless of log host, use your text editor’s
line-sorting feature or a utility similar to the UNIX sort command.
17.6
Forwarding Logs
CanIt-Domain-PRO has the ability to forward logs on a per-realm basis to other machines using the
syslog protocol.
17.6.1
Enabling Log-Forwarding
By default, CanIt-Domain-PRO will not forward logs. To enable log-forwarding, the CanIt-DomainPRO site administrator must edit the file /etc/mail/canit/canit.conf on each CanItDomain-PRO log host and add the following lines:
[logindexer]
forward logs = yes
17.6.2
Configuring Log-Forwarding
To configure log-forwarding, click on Administration : Forward Logs. The Log Forwarding Page
appears:
Figure 17.5: Log Forwarding Page
Note:
Only the CanIt-Domain-PRO site administrator can configure log-forwarding for arbitrary realms. If
you are a realm administrator, the Log Forwarding Page allows you to configure log forwarding only
for your current realm.
To forward logs for a particular realm:
1. Enter or select the realm name in the Realm column.
17.6. FORWARDING LOGS
209
2. Type the IP address or host name of the destination host in the Log Host column. If you use
UDP transport, you can enter multiple log hosts in a comma-separated list; in this case, log
lines will be forwarded to each host. Additionally, you can use a different port for each host by
following the host name or IP address with /port.
If you use TCP transport, then you can only enter a single log host and cannot override the port.
3. Enter the port number in the Port column. The standard SYSLOG port is 514.
4. Select the transport (either UDP or TCP) from the Transport column.
To disable forwarding for a realm, delete the entry with the Delete? check box, or enter a blank string
for the host name.
Note:
Forwarded logs are always forwarded with the mail facility and info priority, regardless of the
original priority. Also, the entire original log line is forwarded including a high-resolution time-stamp.
The receiving machine may log some redundant information with each received log line because of
the way it is forwarded.
Because CanIt-Domain-PRO must correlate log lines and ensure that all lines pertaining to a realm
are forwarded (and no lines not pertaining to the realm are inappropriately forwarded), logs are not
forwarded in real-time. There may be a delay of up to 30 minutes between a line being logged on the
CanIt-Domain-PRO system and the line being forwarded to the remote host. Nevertheless, the original
timestamp is preserved.
210
Chapter 18
Tips
Managing spam requires constant attention, but there are many things you can do to reduce the workload of the administrator. This chapter offers advice for fine-tuning CanIt-Domain-PRO and making
it more effective.
18.1
Note:
Greylisting
In the past, spammers would use open SMTP relays to send spam. With the advent of inexpensive
residential broadband, many spammers use special software to send bulk mail directly from their PC’s.
Because spammers want wide distribution, they want each message to be sent as cheaply as possible.
Some spam software, therefore, ignores SMTP errors if a message cannot be delivered.
CanIt-Domain-PRO can deal very effectively with software that never retries by sending a temporary
failure indication at the end of DATA when mail from an unknown sender arrives. If you set the
“Tempfail unknown senders on first transmission” stream setting to Yes, then CanIt-Domain-PRO
uses the combination of sender e-mail address, recipient e-mail address, sending relay IP address
and message subject to calculate a hash. If this hash has never been seen before, CanIt-DomainPRO tempfails the message. Once the hash reappears, CanIt-Domain-PRO marks the host as “known
to retry” and lets the message to proceed to content-scanning. A host marked “known to retry” is
allowed to bypass greylisting for 40 days.
There are some down-sides to using greylisting. Valid mail from new senders may be delayed by
anywhere from 15 minutes to four hours, depending on the retry interval on the sending relay. You
can avoid this delay by setting up a secondary MX record. In fact, you can simply give the CanItDomain-PRO machine a virtual interface with another IP address and publish this other IP address as
a secondary MX record. In this way, when proper SMTP relays receive a temporary failure indication
on the primary MX machine, they immediately try to send to the secondary MX machine. Often,
spamware won’t retry.
On a similar note, CanIt-Domain-PRO will not issue temporary failures for messages relayed from
any server in a Known Network with Skip Greylisting configured (see Section 5.7 on page 65). If
211
212
CHAPTER 18. TIPS
a message is received by such a server, greylisting will not be used. In some cases, this can cause
greylisting statistics to be skewed. For example, if mail is initially received by a CanIt-Domain-PRO
server and marked as greylisted, then is received by a secondary MX server and either relayed to the
CanIt-Domain-PRO server, or to an internal mail server, the message will appear in the CanIt-DomainPRO statistics as having been greylisted, even if it was received and processed.
In general, we find that setting Tempfail unknown senders on first transmission to Yes is a cheap
and effective way to reduce spam.
WARNING: Some mailing list programs use “disposable” sender addresses which always change.
These lists do not work well with greylisting. To work around the problem, you should whitelist the
domain of the mailing list sender.
CanIt-Domain-PRO tries to detect disposable-address schemes. It ignores everything in the sender
address following a plus sign or a dash followed by a digit. These rules catch most common methods
for generating disposable addresses, but they are not exhaustive.
18.2
Don’t Trust Sender Addresses
Many spammers use one-time disposable sender addresses. Many addresses are not even valid. We
do not recommend blacklisting addresses unless you receive many different spam messages from the
same address. Therefore:
Blacklisting individual addresses is usually not effective. Whitelisting known good
addresses (for example, mailing-list sending addresses) can be very effective. The sender
report may, however, highlight a persistent spam sender address which is worth blacklisting.
18.3
Don’t Trust Sender Domains
Just as sender addresses are often fake, sender domains are too. However, some domains are known
spammers and these can be profitably blacklisted. The tip:
Blacklisting entire domains can be effective under limited circumstances. Whitelisting domains is generally a bad idea because spammers often fake mail from good domains. Holding all mail from free e-mail services like Hotmail and Yahoo can be effective
if you use it in conjunction with whitelisting of known good senders from those services.
Use the domain report to help make these decisions.
18.4
You May Trust Relay Hosts
It is rather difficult to fake the IP address of the SMTP relay host, so this attribute can usually be
trusted. We recommend using a DNS-based blacklist service in your Sendmail configuration file or
the CanIt-Domain-PRO GUI to reject the most obvious offenders. However, if you receive multiple
spam messages from a given relay host, it can be effective to block the host:
18.5. CUSTOM RULES
213
Blacklisting a repeat-offender relay host is effective. Whitelisting known good hosts
such as internal hosts is effective and recommended. Use the host report to determine
which hosts are persistent spam relays.
18.5
Custom Rules
18.5.1
General Recommendations
There are a few custom rules which are quite effective:
1. If you know that your CanIt-Domain-PRO server only accepts inbound mail from the Internet,
then no server should ever claim to be in your domain in the HELO command. If your CanItDomain-PRO server is called canit.mydomain.tld, a custom rule to add 5 points if HELO
ends with mydomain.tld can be very effective. In fact, you might want to make high-scoring
rules which automatically reject messages with obviously-fake HELO arguments.
2. Similarly, no machine should ever put an IP address as the argument of HELO. Some spammers
use random IP addresses here to confuse spam-reporting tools. A custom rule which “regexpmatches” HELO against ˆ\d+\.\d+\.\d+\.\d+$ can be quite effective.
3. Custom rules which specify Sender contains “offer”, “bounce”, “return” and “noresponse” can
often trap spam. You should use only moderate scores on these rules, because some legitimate
mail comes from such senders. However, adding a rule which scores around 3 for these patterns
can help catch a lot of spam which might otherwise sneak under the scoring threshold.
4. Subject-matching rules for the most obnoxious spams are very effective. For example, Subject regexp-match rules against v\Sagra and (increase|enlarge).*penis are very
effective.
18.5.2
Things to avoid
Be very careful when writing custom rules, especially rules that can match on the message body.
For example, a straightforward rule that contains “cum” in the body will match mail containing mail
containing “document”, “cumulative”, “modicum” and at least 64 other common English words. Similarly, “sex” will match “sexton”, “Essex” and others.
If you want to match words in a message body, we recommend that you use a regular-expression
match, and use Perl’s word-boundary operators. For example, the Perl regular expression \bcum\b
matches the word “cum”, but not “document”, “cumulative” or “modicum”.
18.6
Group High-Scoring Messages Together
We recommend that you set the default sort order to sort by Score, Descending. This groups highscoring messages at the beginning and low-scoring messages at the end of the pending list. This makes
it easier for the spam-control officer to dispose of the messages.
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CHAPTER 18. TIPS
18.7
Roaring Penguin Best-Practices
At Roaring Penguin Software Inc., we’ve spent quite a bit of time analyzing spam and spammers. You
may wish to try out some of our anti-spam rules to see if they work well for you. Here is a quick
summary of the rules we use; they may inspire you to develop your own anti-spam rules.
• We use custom rules to add 4 to any message whose Sender contains “offer”, “noresponse”,
“remove”, “marketing” or “promo”. These rules may be a touch aggressive for very busy sites,
but are quite effective for smaller sites.
• Another custom rule adds 1.2 to any Relay containing “[” (left square bracket.) This indicates
a reverse-DNS failure on the sending host, which is mildly correlated with spamming.
• We use a Spam threshold of 4.6, because we find the default of 5 is somewhat conservative.
• We use a discard threshold of 20; this seems quite safe.
• We set Tempfail unknown senders on first transmission to Yes. Again, this may be unacceptable for some sites.
18.8
General Anti-Spam Tips
18.8.1
Use Receive-Only Addresses on your Web Site
Spammers love to extract e-mail addresses from Web sites, and not only do they use them for the
obvious purpose of spam targeting, but also they use them as fake sender addresses.
Therefore, we recommend a general policy of publishing only generic e-mail addresses on your Web
site, like [email protected] and [email protected]. When you reply
to inquiries, always use a real, personal e-mail address like [email protected]. This has
two benefits:
1. If someone sends e-mail purporting to come from [email protected], you know
immediately that it is spam, and you can reject it. You can blacklist all your generic addresses
inside CanIt-Domain-PRO.
2. If someone complains about receiving e-mail from one of the generic addresses, you can point
to your policy and assure the recipient that the sender address was faked.
18.8.2
Do Not Reply to Spam
Do not ever reply to spam e-mail; such replies simply serve to validate your e-mail address. Similarly,
do not visit Web sites purporting to offer opt-out services; they also serve to validate your address for
further spamming.
Chapter 19
Security
Running a secure CanIt-Domain-PRO installation is relatively straightforward, but there are many
issues you have to watch out for. This chapter gives you guidance on how to secure your CanItDomain-PRO installation.
19.1
Don’t Run as Root
The most basic security principle is to run as little software as root as possible. Therefore:
• Always create the Sendmail smmsp user and group, and do not run Sendmail suid-root. Instead,
the permissions on the Sendmail executable should look like this:
-r-xr-sr-x root smmsp sendmail
That is, the sendmail binary should be owned by root, group smmsp and have mode 2555.
• Always create the MIMEDefang defang user and group, and run MIMEDefang as defang. In
/etc/mail/canit/canit.conf, enable mx user=defang in the [mimedefang]
section.
19.2
Ownership and Permissions
All system configuration directories like /etc and their ancestors and descendants should be owned
by root and writeable only by root. Here are suggested ownership and permissions for various files
and directories. Note that where we use group root, your system may use wheel or some other group
for root-owned files.
File or Directory
/etc/mail/canit and ancestors
/etc/mail/canit/canit.conf
/var/spool and ancestors
/var/spool/MIMEDefang
/var/spool/MD-Bayes
/var/lib/canit-storage-manager
The PHP files in Apache’s Web space
Owner
root
apache
root
defang
defang
defang
root
Group
root
defang
root
defang
defang
defang
root
Mode
0755
0640
0755
0700
0755
0700
0644
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CHAPTER 19. SECURITY
19.3
SSH
The various nodes in a CanIt-Domain-PRO cluster communicate via SSH. Each node must be able to
SSH to all other nodes on port 22.
For intra-cluster communication to work, root SSH login must be permitted. However, you do not
need to permit general root login because the CanIt-Domain-PRO nodes only use a forced command
for communication. The safest setting in /etc/ssh/sshd config is therefore:
PermitRootLogin forced-commands-only
19.4
PostgreSQL Security
By default, PostgreSQL trusts any connection coming from the local host.
Therefore, if you use PostgreSQL on your CanIt-Domain-PRO server with the default access rules,
do not allow normal users to have shell accounts on the CanIt-Domain-PRO server. This cannot be
emphasized strongly enough: If you allow normal users shell access on the CanIt-Domain-PRO server
with PostgreSQL’s default setup, anyone can access or change the spam database.
If you must allow shell accounts on the CanIt-Domain-PRO server, then you must password-protect
your PostgreSQL installation. See the PostgreSQL documentation (“Authentication Methods” section)
for details. You must also protect your database passwords:
• The file /etc/mail/canit/canit.conf must be owned by apache and group defang.
Both the defang user and the apache user need read-access to these files, which should have
mode 0640. (We assume your Web server runs as user apache; if not, substitute the Web server
user as appropriate.)
For best security, we strongly recommend that you do not allow ordinary users to have shell accounts
on your mail server. If the CanIt-Domain-PRO database server is on a different machine, you should
not permit shell accounts on that machine either.
19.5
PHP Security
PHP has a parameter called register globals, which automatically sets global variables based
on GET, PUT or COOKIE variables. This setting may be a security risk, and CanIt-Domain-PRO does
not require it. We strongly recommend that you set register globals to off.
19.6
Network Security
When you log on to CanIt-Domain-PRO, your username and password are transmitted in cleartext.
While you interact with CanIt-Domain-PRO, your browser passes a session cookie back so CanItDomain-PRO can keep track of your session. Both your password and the cookie are vulnerable to
19.7. BACKUPS
217
network sniffing. If you interact with CanIt-Domain-PRO over an untrusted network, or a network
whose traffic may be sniffed, you should use HTTPS and SSL encryption. Setting this up is beyond
the scope of this manual, but CanIt-Domain-PRO should operate with no changes over HTTPS.
19.7
Backups
The daily CanIt-Domain-PRO cron job dumps a text backup of the spam database to the file
/var/spool/Canit-Spam-DB-Backup/SPAM-DATABASE-BACKUP. You should back this
file up regularly in case the CanIt-Domain-PRO server suffers a hardware or other problem. You
should also make sure the file is not readable by normal users.
You should also back up the entire directory tree rooted at /var/spool/MD-Bayes. If you are
using the Storage Manager, you should also back up the Storage Manager directory on each Storage
Manager node.
Some CanIt-Domain-PRO settings are stored in /usr/share/canit as well as
/etc/mail/canit; you should back up that directory any time that you change a file in it.
You may wish to back up /etc/mail in its entirety to capture Sendmail configuration files in your
backup as well.
See Section E.3 for more information on automating backups to a remote location.
Note:
When restoring from backups, never replace existing /etc/mail/ or /usr/share/canit files
with backed up versions! Rather, use your backup versions as reference.
Finally, please remember to back up any customizations you have made to your CanIt-Domain-PRO
installation, including web interface files, custom account-info or other scripts, et cetera.
Note:
When restoring from backups, be careful when replacing web interface files, especially (but not only)
if you are restoring to a different version of CanIt-Domain-PRO than that from which your backup
was made.
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CHAPTER 19. SECURITY
Appendix A
The Domain Configuration Wizard
A.1
Introduction
The Domain Configuration Wizard provides a simple way to quickly configure the most important
settings for a domain. All of the pages in the Domain Configuration Wizard are available in greater
detail in the Setup and Administration menus. However, because the Domain Configuration Wizard
centralizes the important settings in one simple workflow, you may prefer to use it to set up new
domains.
To access the Domain Configuration Wizard, click on Setup and then Wizards. Click on Domain
Configuration Wizard.
A.2
Entering the Domain Name
The first step in the Domain Configuration Wizard requires you to enter a domain name. (Figure A.1).
Enter the domain name and click Next.
Figure A.1: Domain Configuration: Enter Domain Name
A.3
Picking a Realm
In the next page (Figure A.2), you are prompted to select a realm name. Enter the realm name and
click Next.
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220
APPENDIX A. THE DOMAIN CONFIGURATION WIZARD
Figure A.2: Domain Configuration: Enter Realm Name
You may type the name of an existing realm, in which case CanIt-Domain-PRO maps the new domain
into that realm. Or you may enter a new realm’s name, in which case the realm will be created and the
domain will be mapped into that realm. If no data for the new domain exists yet, CanIt-Domain-PRO
will suggest a realm name based on the domain name.
A.4
Configuring Streaming
The next step (Figure A.3) requires you to choose how mail for the domain should be streamed.
Streaming is explained in detail in Chapter 4.
Figure A.3: Domain Configuration: Configuring Streaming
You can configure streaming in several ways:
A.5. CONFIGURING AUTHENTICATION
221
• You can simply chop the domain part off the e-mail address so that mail for
[email protected] goes into the stream user.
• You can chop the local part off the e-mail address so that mail for [email protected]
goes into the stream example.net.
• You can keep the entire e-mail address as the stream name. This is the recommended method
for most installations.
• You can invoke the User Lookup Wizard to set up a more complex streaming method (for
example, using LDAP). The User Lookup Wizard is described in Chapter 7.
Note that if you have created User Lookup methods (either in the past or after stepping through the
User Lookup Wizard from the Domain Configuration Wizard), you will be presented with additional
choices for streaming.
A.5
Configuring Authentication
Once streaming has been configured, you will be asked to configure authentication (Figure A.4).
Figure A.4: Domain Configuration: Configuring Authentication
222
To allow end-users to log into CanIt-Domain-PRO and manage their quarantines, you can set up an
authentication mechanism. From the Domain Configuration Wizard, you have several choices:
• IMAP allows you to authenticate users against an IMAP server.
• POP3 allows authentication against a POP3 server.
• Other allows you to skip setting up authentication. You can do it at a later time, or (if you do not
want to allow end-users to log in) skip it entirely. You can also step through the User Lookup
Wizard to set up a more complex authentication mechanism.
If you select IMAP or POP3, you will be prompted to enter the name (or IP address) of the IMAP or
POP3 server. If CanIt-Domain-PRO should strip the domain name off the login name before attempting to authenticate, set the “Strip domain name from login” parameter to Yes. You can also configure
CanIt-Domain-PRO to validate SSL certificates and to use (or require) an encrypted connection to the
POP3 or IMAP server.
If you step through the User Lookup Wizard to create an authentication method, the newly-created
method will be presented as an authentication choice when you return to the Domain Configuration
Wizard.
A.6
Configuring Routing and Verification
Finally, CanIt-Domain-PRO will ask you to configure routing and verification (Figure A.5).
Figure A.5: Domain Configuration: Configuring Routing and Verification
A.7. SUMMARY
Note:
223
Configuring routing via the Web interface is only available on CanIt-Domain-PRO appliance builds.
If you are not running an appliance build, you will need to configure routing using Sendmail’s mailertable feature; consult the Sendmail documentation for details.
To route mail for the domain, enter the host name or IP address of the back-end SMTP server that will
accept e-mail for the domain.
We strongly recommend configuring some method for CanIt-Domain-PRO to validate recipient addresses. If you do not validate recipient addresses, CanIt-Domain-PRO is forced to accept mail for
any address withing the domain, likely resulting in many failure notifications.
If your back-end mail server validates recipients during the SMTP transaction, enter its name or IP
address as the verification server. If it does not, you will have to leave the verification server blank
and use some other method (such as LDAP streaming) to validate recipients.
A.7
Summary
After configuring routing and verification, CanIt-Domain-PRO will display a summary of your settings. Click Finish to make them take effect.
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Appendix B
Release Notes
Version 10.0.2 released on 2016-09-13
• BUG FIX: A few places in the Web interface would forget the “rlm” and “s” parameters when
navigating from page to page; this has been fixed.
• BUG FIX: In certain very unusual cases, aliasing could fail for locally-generated mail. This has
been fixed.
• BUG FIX: Immediate Locked Address functionality has been fully enabled in the GUI and they
have been made case-insensitive.
• NEW FEATURE: The Locked Address feature has been enhanced with a variation called “Immediate Locked Addresses” that lets you create a locked address without informing CanIt beforehand.
• NEW FEATURE: An SMTP Server Test module lets you run a test against a back-end SMTP
server and receive helpful debugging output as well as some explanatory comments.
• POLICY CHANGE (CanIt-Domain-PRO only): The Setup > Domain Routing page now shows
domains associated with the current realm and all of its subrealms. Before, it would show
everything (for the site administrator) and only those domains in the current realm (for realm
administrators).
• MINOR NEW FEATURE: You can limit the ConnectWise and Autotask updates to run on
specific days of the month.
• CHANGE: If the country of a sending server can be determined, that country’s flag is displayed
in the “Sender” column of the quarantine display.
• IMPROVEMENT: Delivery Policy Rules have been extended with new actions and made more
flexible with the ability to use macros inside action parameters.
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APPENDIX B. RELEASE NOTES
• IMPROVEMENT: The Valid Recipients Table now also automatically includes aliases, explicit
stream mappings, and in-realm email addresses in the users table. This greatly reduces the
amount of duplicate data you need to enter into CanIt to make use of the Valid Recipients
feature.
• IMPROVEMENT: Pending Notifications include a hazard icon near the subject of quarantined
messages if they contain a held filename extension.
• COSMETIC FIX (CanIt-Domain-PRO only): If a domain is associated with many Known Networks, only the first four are shown to avoid huge amounts of data in Administration > Provisioning.
• BUG FIX: Removal of pre-existing inline HTML voting links is now far more reliable than
before, even in the face of mangling by mail readers.
• BUG FIX: The “is not” relation in Archive Search rules would generate invalid SQL, causing
an exception to be thrown. This has been fixed.
• BUG FIX: The SRS feature would sometimes cause locally-generated delivery status notifications to be lost completely. This has been fixed.
• BUG FIX (CanIt-Domain-PRO only): The RSS URL Base URL was taken from the “base”
realm instead of the correct realm.
• BUG FIX: The failover setup code would create the recovery.conf file with wrong ownership.
This has been fixed.
• MAJOR IMPROVEMENT (CanIt-Domain-PRO Only): Autotask integration has been revamped completely; the new code supports any billing cycle (not just monthly billing on the
first of the month) and all possible CanIt products including inbound and outbound filtering,
Secure Messaging and Archiving.
• IMPROVEMENT: Additional Delivery Policy actions that allow changing the domain of the
sender.
• IMPROVEMENT: Additional tests for Compound Rules including arrival-time-based tests.
• IMPROVEMENT (Secure Messaging Only): All outbound secure messages are stored in the
sender’s “Sent” folder—not just messages that are created within the Secure Messaging interface.
• UPDATE: Update ClamAV from 0.99.1 to 0.99.2.
• COSMETIC FIX: If an incident is held because of a Filename Extension rule, it is annotated
with a little hazard icon.
• COSMETIC FIXES: Minor tweaks to theme CSS files.
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• BUG FIX: The DMARC code was incorrectly using the DMARC record associated with the
DKIM “d=xxx” tag rather than the RFC5322.From domain. This has been fixed.
• BUG FIX: The code to retrieve held attachments could fail with Internet Explorer if the attachment filename had accented characters. This has been fixed.
• BUG FIX (Secure Messaging Only): Secure Messaging users can log in with their CanIt credentials. This was partly implemented in the previous release, but did not work properly in all
cases.
• BUG FIX (Appliance Only): The log-line parser could sometimes misinterpret message IDs
containing a “%” followed by two hex digits.
• BUG FIX (Appliance Only): A fatal PHP error in log searching has been fixed.
• BUG FIX: In previous release, the domains associated with a Known Network were displayed
in random order. They are now properly sorted.
• MAJOR NEW FEATURE: A new Delivery Policy Module lets you create rules that affect how
mail is delivered after CanIt has scanned it and is about to deliver it.
• MAJOR NEW FEATURE (CanIt-Domain-PRO Only): CanIt can integrate with ConnectWise
to automate billing.
• POLICY CHANGE: In addition to looking up exact matches in the Address-to-Stream table
first, CanIt now also looks up local parts with wildcard domains. In other words, the order of
lookups for “[email protected]” is now:
1: [email protected] 2: user@* 3: Whatever Domain Mapping is defined for example.com
• IMPROVEMENT (Debian Appliances Only): Sender, Network, Domain, Filename Extension
and MIME rules all have statistics on how many times they hit.
• IMPROVEMENT (Secure Messaging Only): If a recipient already has a CanIt account, he or
she can log into that account to access the Secure Messaging portal rather than having to create
a completely separate account.
• IMPROVEMENT: The URL Proxy feature has a third option for whether or not to wrap a URL.
In addition to “Wrap” and “Don’t Wrap”, you can now specify “Wrap if Tagged as Spam” which
wraps URLs only if a message was tagged as spam in tag-only mode.
• IMPROVEMENT: In Pending Notifications (HTML Format), the full name in the From: header
is included, in addition to the email address.
• IMPROVEMENT: A new “Iceberg” Web interface theme has been added to the standard themes
shipped with CanIt.
• COSMETIC FIX: Minor CSS fixes to the default RP-Web theme.
228
• BUG FIX: canit-failover-init.pl could fail on versions of PostgreSQL higher than 9.1 that also
use tablespaces. This is a very unusual configuration and not likely to be a problem in practice.
• BUG FIX: Releasing an incident by clicking on the notification email link could appear to work,
but actually fail if you are logged in as a user who lacks access to the original stream. This has
been fixed.
• BUG FIX: Many more filename extensions are recognized as MS Office documents and scanned
for macros.
• BUG FIX: The one-time key encryption method could fail if you tried repling to an encrypted
message. This has been fixed.
• BUG FIX: Log query searches header From: field when sender is specified.
• NEW FEATURE: Users with sufficient privilege can request specific domains to be exempted
from URL-proxying.
• NEW FEATURE: CanIt can detect PDF files that contain JavaScript; if found, it adds the
pseudo-filename “canit js found.js in pdf” to the list of attachments. (CanIt Appliances and
Hosted CanIt only.)
• NEW FEATURE: CanIt can extract URLs from PDF documents for testing against the knownphishing list. (CanIt Appliances and Hosted CanIt only.)
• POLICY CHANGE: Roaring Penguin no longer supports new source or RPM installations; all
new installations must use our ISO or be converted to an appliance from Debian. The source
and RPM packages will continue to be maintained for the purpose of upgrading legacy CanIt
installations.
• POLICY CHANGE: In tag-only mode, CanIt would unconditionally add a tag with the “detail”
field. It no longer does that; instead, you should explicitly include “%e” in your tag string if you
want the detail included.
• IMPROVEMENT (Archiver): When replying to a message within the Archived Mail interface,
you can request CanIt to Cc: the sender.
• MINOR IMPROVEMENT: Filename Extensions of attachments are logged in the “what=xxx”
mail log line as the “attach types=xxx;yyy;zzz” keyword.
• SECURITY IMPROVEMENT: Make sure all local passwords use the stronger MD5-style encryption rather than traditional UNIX-style password encryption.
• MINOR IMPROVEMENT: Implement “Show Changes” on Setup > Known Networks page.
• BUG FIX: If a message has been forced to a stream because of a Known Networks entry, we
skip SPF, DKIM and DMARC lookups.
229
• BUG FIX: In a few places in unusual circumstances, an uncaught exception could kill the scanning process and tempfail mail. This has been fixed.
• BUG FIX: The “Contains Credit-Card” Compound Rule component was a bit lax and could
falsely claim an email contains a credit card number; the code has been tightened up to reduce
false-positives.
• BUG FIX: Several other minor filtering and GUI bugs were fixed.
• BUG FIX: If a file has trailing space (for example, “malware.js ”), then CanIt ignores the trailing space when applying Filename Extension rules. In this example, the extension would be
considered to be “js”.
• MINOR NEW FEATURE: DMARC can now be run in a “Quarantine” mode. In this mode, it
quarantines messages that hit DMARC “reject” or “quarantine”. The “Enforce” mode is stricter
and it rejects messages with a DMARC result of “reject”.
• IMPROVEMENT: A new pulldown menu style is available for the RP-Web and Postmodern
themes; these menus let you navigate with only one click to any first- or second-level menu
page. By default, pulldown menus are disabled but users can enable them under Preferences.
• IMPROVEMENT (CanIt-Domain-PRO only): Autotask integration has been improved; if a
Contract has a purchase order associated with it, the PO number is copied into the invoice
posted by CanIt.
• BUG FIX: DMARC results are always added to the incident report, even in dry-run mode.
• BUG FIX: DKIM and DMARC would sometimes incorrectly use the address in the Sender:
header rather than the From: header. This has been fixed.
• BUG FIX: Minor cosmetic errors in the Web interface HTML were corrected.
• BUG FIX: The login page templates now respect theme customizations.
• MAJOR NEW FEATURE: CanIt now supports testing for DMARC policy. However, DMARC
reporting is not yet implemented.
• MAJOR NEW FEATURE (Secure Messaging only): You can now elect to use a new one-time
key encryption scheme. In this scheme, the decryption key is encoded in the URL sent to the
original recipients. It is impossible to decrypt the message without possessing the URL, even if
someone obtains the recipient’s Secure Messaging credentials.
230
• POLICY CHANGE: By default, non-administrative users can no longer vote URLs as fraudulent. However, this permission can be granted to them under Administration : Permissions
should you deem it appropriate.
• CHANGE: We no longer offer Red Hat Enterprise Linux 5 RPM packages. We still offer RPMs
for Red Hat Enterprise Linux 6.
• MINOR IMPROVEMENT: If the “From:” header address is different from the envelope sender,
an additional “header [email protected]” key pair appears in the “what=...” line
logged by CanIt.
• MINOR IMPROVEMENT: The Known Networks page is now paginated, yielding much faster
display times for sites with many Known Networks entries.
• MINOR IMPROVEMENT (CanIt-Domain-PRO only): The Provisioning page displays Known
Networks associated with outbound relaying for a given domain.
• MINOR IMPROVEMENT: (CanIt-Domain-PRO only): A new Provisioning History page
shows provisioning statistics per realm over time.
• IMPROVEMENT: The LDAP code is much more intelligent about guessing a user’s primary
email address from the LDAP attributes that are returned. In particular, it understands Microsoft’s convention that the primary address is prefixed by SMTP: (upper-case) as opposed to
smtp: (lower-case).
• MINOR IMPROVEMENT: The API call GET /info returns some additional info for rootprivileged users (in CanIt-Domain-PRO, only base-realm root-privileged users.)
• MINOR IMPROVEMENT: The /xauth API call accepts a “logout redirect” parameter. This
permits you to redirect to a page that logs a user out of an entire single sign-on system when he
or she logs out of CanIt.
• MINOR IMPROVEMENT: The Verification Server code attempts to detect a back-end server
that is imposing “tarpitting”. It raises an anomaly if tarpitting is suspected.
• CHANGE: The maximum possible timeout for Verification Server checks has been increased to
120 seconds from 30 seconds.
• BUG FIX: The Anomaly Notification nightly task would sometimes use templates from the
wrong realm when composing its email. This has been fixed.
• BUG FIX: In several places, the code incorrectly assumed that the force to stream Known Networks attribute applied on inbound-only hosts when in fact it does not. This bug has been fixed.
• NEW FEATURE (Archiver only): Users with the appropriate permission can compose brand
new email messages within the Archiver web interface. This lets you keep doing business if
your back-end mail server is down.
231
• IMPROVEMENT (CanIt-Domain-PRO only): The provisioning report under Administration :
Provisioning is now calculated much more quickly than before.
• IMPROVEMENT: If an email is rejected because of SPF “fail”, the SPF error message is included in CanIt’s 5xx reply.
• POLICY CHANGE: Normal end-users can be granted permission to make URL Proxy rules.
Before, only administrators could do so.
• DEPRECATION: The old and deprecated canit-api-client command-line tool has been removed.
Instead you should use the new canit-api-wrapper tool. As part of this change, the /introspection
API call has been removed.
• MINOR IMPROVEMENT: The report pages with the long list of possible classifications let you
set, clear and toggle all the classifications with one mouse click.
• BUG FIX: SPF/DKIM VBR lookups would be ignored in favour of a wildcard SPF/DKIM rule.
This has been fixed so that wildcard rules do not override VBR rules.
• BUG FIX: A long-standing bug in the Permissions user-interface that appeared to make permissions change by themselves has been fixed.
• BUG FIX: The URL proxy landing page now checks for both the original URL and the base
URL (no query parameters) in the list of known-phishing URLs.
• BUG FIX: CanIt would sometimes raise an anomaly complaining that a domain’s DKIM DNS
record does not match the DKIM key, when in fact the two do match. This has been fixed.
• BUG FIX: The URL proxy correctly handles the <base> tag.
• BUG FIX: The CanIt Storage Manager would sometimes log incorrect storage-manager traffic
statistics; the statistics-logging module has been overhauled to correct this.
• NEW FEATURE: A Compound Rule can refer back to the list of other rules hit so far, allowing
the powerful composition of “meta rules”. See the manual for details.
• NEW FEATURE (Appliance Only): The log lines resulting from a log search can be downloaded as plain-text.
• IMPROVEMENT: The OfficeMacroAutostart test was split into three tests that look for
Auto Open, Document Open and Workbook Open macros in MS Office documents; you may
wish to score the different macros differently.
• POLICY CHANGE: Automatic updates are disabled for appliances running PostgreSQL earlier
than 9.0. Such appliances can still be upgraded by hand.
• BUG FIX: The alias-replacement mechanism would sometimes deliver to both the original and
the aliased address if the original address was mixed-case. This has been fixed.
232
• BUG FIX (Appliance only): An error parsing a logline containing “forced into stream xyz:abc
(derived from xyz:@@)” has been fixed.
• NEW FEATURE: A new test plugin called OfficeMacroAutostart detects macros in MS Office
documents that are designed to start as soon as the document is opened. Such macros are highly
suggestive of macro viruses.
• PERFORMANCE IMPROVEMENT: On busy systems, the Archive Indexer background process can run with multiple concurrent indexing processes. See the Administration Guide documentation of the configuration setting [ticker] index archived mail parallel indexers.
• BUG FIX: It is not possible to filter the top rule hits by domain, so remove the domain box from
the corresponding report Web page.
• NEW FEATURE: Each domain associated with a Known Network may have its own separate
“Force-To-Stream” entry. This provides additional flexibility for dealing with outbound mail.
• NEW FEATURE (CanIt-Domain-PRO Only): A new page Administration : Provisioning shows
usage information in a way that is convenient for billing.
• MINOR IMPROVEMENT (Appliance Only): Hovering over the “Hits” column on rule pages
shows the date the rule last fired, assuming Hits is non-zero.
• BUG FIX: There were extensive fixes to the handling of Unicode data throughout CanIt. These
fixes include safer handling of malformed messages with octets > 127 directly in the headers.
• BUG FIX (Appliance Only): Custom Rules now sort on the “Hits” column correctly.
• BUG FIX: Various parse errors in the pure-PHP MIME parser were fixed.
• BUG FIX: Fix deprecated way of using “crypt” function in PHP.
• MINOR IMPROVEMENT: If DKIM signing is set up, but no DKIM DNS records have been
published for a domain, the nightly cron job will raise an anomaly warning.
• BUG FIXES: Fixed a number of problems with UTF-8 data encoding on Debian Jessie, caused
by an upgraded version of the PostgreSQL perl client library.
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• MINOR NEW FEATURE: You can download the complete raw MIME message when viewing
a held message.
• MINOR NEW FEATURE: The interval between Storage Manager latency checks is configurable rather than being hard-coded at one hour.
• MINOR NEW FEATURE: “match”-type DNSBLs now permit the specification of ’X’ as an
octet; this acts as a wildcard that matches anything from 0 to 255.
• UPDATE: Our appliance ISO is now based on Debian 8 “Jessie” and we have Jessie packages
available to upgrade appliances to Jessie.
• END-OF-LIFE: 9.2.6 will be the last version for which Debian 5 “Lenny” packages will be
made available.
• BUG FIX (Appliance only): The log-searching page could lose track of the current search if
you clicked on an arrow to sort results. This has been fixed.
• BUG FIX: CanIt now treats “permerror” as “error” for the purpose of SPF scoring.
• BUG FIX (Secure Messaging only): Properly quote the header From: full name.
• BUG FIX (Secure Messaging only): The subject could be truncated in the message display if
the subject header was wrapped. This has been fixed.
• BUG FIX: Streamed messages could end up using the wrong IP address for DNSBL lookups.
• BUG FIX: A typo prevented the xauth API call from working correctly without a ’redirect’
parameter; this has been fixed.
• NEW FEATURE: CanIt now supports aliases of the form:
*@domain1.example.org ==> %[email protected]
which rewrites the domain part while keeping the original local part. This achieves so-called
Domain Aliasing.
• NEW FEATURE (Secure Messaging only): Administrators can disable Secure Messaging accounts. In addition, realm administrators can delete Secure Messages associated with their
realms.
• IMPROVEMENT: The DKIM key-pair page lets you specify a DKIM selector. This allows for
graceful rollover of keys.
• IMPROVEMENT: The DKIM signature algorithm has been changed from rsa-sha1 to rsasha256
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• UPDATE: SpamAssassin has been updated from version 3.3.2 to 3.4.1
• UPDATE: ClamAV has been updated from version 0.98.6 to 0.98.7.
• BUG FIX (CanIt Appliance only): The Log Indexer would index the source and destination
IP addresses as 127.0.0.1 for streamed messages, instead of using the correct external relay
addresses. This has been fixed.
• BUG FIX: CanIt::Sendmail’s SMTP timeout was too short, which could result in duplicate
Pending Notification messages on busy systems. This has been fixed.
• BUG FIX: A rounding problem could result in duplicate pending notifications for a given incident even if the “Only notify me about new incidents” flag is set. This has been fixed.
• BUG FIX: Accepting an incident multiple times in quick succession could result in multiple
copies being remailed. This has been fixed.
• BUG FIX: A streamed message coming in originally over IPv6 could have the wrong hostname
associated with the relay IP. This has been fixed.
• BUG FIX: The “Vote as Phish/Fraud” link did not actually permit voting on malicious URLs.
• BUG FIX: The code to handle “Associated Domains” with Known Networks treated domain
names case-sensitively. This has been fixed.
• MAJOR NEW FEATURE: Users can mark messages as fraudulent and then specify which
URLs in the message look malicious. Administrators can add those URLs to the Known Malicious URL list; additionally, they are reported back to Roaring Penguin via our reputation
system.
• MAJOR NEW FEATURE: CanIt can DKIM-sign outbound mail.
• NEW FEATURE (Appliance only): We package and enable code to pull down additional selected ClamAV signature sets.
• IMPROVEMENT: You can specify exactly which domains should be relayed from a given
known network. (By default, if a known network has the ”allow relaying” flag on, then any
message from that network is relayed regardless of the sender domain.)
• IMPROVEMENT: The URL Proxy feature can proxy the target URL of forms as well as ordinary links.
• IMPROVEMENT (CanIt-Domain-PRO appliance only): The Autotask integration code allows
you to specify a minimum number of units to bill each month.
• IMPROVEMENT: The OfficeMacros test is better at detecting macros inside modern MS Office
files.
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• IMPROVEMENT: SMTP Extended Status codes have been changed to better reflect the nuances
of the response. For example, the nonexistent recipient code changed from 5.7.1 to 5.1.1 which
is more appropriate according to the RFC.
• IMPROVEMENT (Appliance Only): Log searching was made more flexible (additional operators are now possible for various fields) and a few minor bugs were fixed.
• UPDATE: Update ClamAV from version 0.98.5 to 0.98.6.
• CHANGE (CanIt-Domain-PRO only): The API call to rename realms allows you to skip renaming the realm in the statistics and log-index tables, which can be extremely time-consuming.
However, if you choose not to rename in the statistics tables, then the realm’s statistics are lost
as is the ability to search logs for the realm prior to the renaming.
• BUG FIX (Archiver only): Some usage reports would crash due to invalid SQL. This has been
fixed.
• BUG FIX: Messages auto-released from delayed streams simply sailed through the system.
Now they are scanned as usual.
• BUG FIX: A race condition in the background task code could result in failures when users
attempted to set up aliases. This has been fixed.
• BUG FIX: An error in the Custom Rule evaluator could make some rules that use regular expressions fail to match correctly. This has been fixed.
• BUG FIX: Anomaly details could contain the incorrect host name. This has been fixed.
• BUG FIX: Messages containing <tr> tags outside of a <table> could mess up the message
preview page. This has been fixed.
• BUG FIX: The web theming system had a small error which made it impossible to change the
color of menu text. This has been fixed.
• BUG FIX: Various errors in extracting URLs for the URL Proxy have been fixed.
• BUG FIX: If a stream is in tag-only mode, we change the wording of “Always Hold” to “Always
Tag”; similar changes occur in various places in the GUI.
• BUG FIX: We add configuration items to /etc/mail/canit/sa-canit.cf to suppress SpamAssassin’s
automatic generation of “trusted” networks.
• MAJOR IMPROVEMENT: CanIt has a test to detect URLs on a Known Phishing URL list and
add points or block messages containing a malicious URL.
• MAJOR IMPROVEMENT: Anomalies now record each individual occurrence of the anomaly
and (if the Log Searching component is installed) include links to relevant log lines.
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• NEW FEATURE: CanIt has code to detect Microsoft Word documents that contain macros.
You can then add points if one is found. This can help combat Word macro viruses, which are
increasingly used to compromise workstations.
• API IMPROVEMENT: The API call “GET /realm/@@/stream/@@/incidents” call permits filter conditions to be supplied to limit the list of incidents that are returned.
• IMPROVEMENT: CanIt parses the text of HTML attachments even if they have type
“application/octet-stream”, as long as their filename ends with .htm or .html and they appear
to contain HTML content.
• IMPROVEMENT: The URL Proxy feature can now proxy HTML form targets as well as normal
“<A>” links.
• IMPROVEMENT: A special notation “>ext” allows you to create Filename Extension rules that
apply only to files found within archive files. Thus, for example, an extension rule of “>zip”
would apply only to a zip file containe in another zip file or some other type of archive.
• IMPROVEMENT: IPv6 geolocation has been improved to include latitude, longitude, city and
region if such data is available.
• POLICY CHANGE: For messages over 9MB in size, CanIt checks against a verification server
even if the recipient is cached as valid. This avoids backscatter with servers that reject large
messages.
• COSMETIC IMPROVEMENT: If a whitelist is ignored due to SPF fail/softfail, the Web interface links to a page that explains what happened.
• BUG FIX: Data supplied for LDAP queries is escaped to avoid inappropriately passing wildcard
characters back to the LDAP server.
• BUG FIX: The Compound Rule entry code now correctly validates entries that are supposed to
be IP addresses.
• BUG FIX: The API call “POST /vote” did not work correctly; this has been fixed.
• MAJOR NEW FEATURE: CanIt now supports SRS (Sender Rewriting Scheme), making it
feasible to use CanIt in front of a back-end server that performs SPF checks. Some configuration
outside of CanIt is required; see the manual for details.
• MAJOR NEW FEATURE: If you are using PostgreSQL’s streaming replication and have a hotstandby database, you can configure certain nodes to direct read-only queries to the hot-standby
server instead of the primary database server. If you have a geographically-dispersed cluster,
this can significantly improve performance by having most queries go to the database server
with the lowest round-trip latency.
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• MINOR IMPROVEMENT (CanIt-Domain-PRO only): The UDP transport for log forwarding
permits you to specify multiple destination hosts, each with its own port.
• MINOR IMPROVEMENT (Appliances only): The “Header From:” email address is logged,
permitting log searches based on that field.
• COSMETIC CHANGE: French and German translations have been updated.
• COSMETIC CHANGE: The “Change Password” page has been reorganized to ask for your old
password first, which matches the way most such pages work.
• BUG FIX: An error in how Compound Rules (and Archiver and Secure Messaging rules) were
compiled down into Perl could result in warnings about undefined values in the mail logs. This
has been fixed.
• BUG FIX: The URL Proxy code could sometimes double-encode MIME messages, breaking
their display. This has been fixed.
• BUG FIX: If a message is relayed from a friendly host, we do not use the HELO information as
Bayes tokens since it is not a reliable indicator of ham/spam.
• BUG FIX: The rate-limiting code could leak rate-limiting information across streams and
realms. This has been fixed.
• BUG FIX: Logins with a full email address but mixed-case domain failed because the domain
lookup was case-sensitive. This has now been made case-insensitive.
• BUG FIX (Archiver and CanIt-Domain-PRO only): The archive zip file page now shows zip
files in the current realm, not necessarily the realm of the logged-in user. This only makes a
difference for realm administrators who have subrealms and switch into them.
• BUG FIX: The PHP code understands a wider variety of MIME “charset=xxx” parameters,
fixing display problems for certain messages.
• BUG FIX (Appliance Only): Fix a typo that broke upgrades against versions of PostgreSQL <
8.4.
• BUG FIX: Fix edge-case in which transitioning from the old hash-based incident detection
algorithm to the new incident-ID based algorithm could sometimes cause existing incidents not
to display in the Web interface.
• POLICY CHANGE: If a CanIt cluster member is *not* marked “Outbound” in the Cluster
Members Table, then the force-to-stream Known Networks attribute is ignored.
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NOTE INCOMPATIBILITY
The above policy change may change how force-to-stream works on your cluster.
• POLICY CHANGE: When CanIt logs a message subject in the “subject=XXX” field, it always
encodes the subject as UTF-8, regardless of the original encoding.
• MAJOR CHANGE: The global setting G-600 ”Send tempfail indications for suspect messages”
has been removed and implicitly defaults to “Never”. Previous versions of CanIt used a hashing scheme to detect message retransmissions; this could fail in rare edge-cases. The hashing
scheme has been removed and incident creation is now far more reliable As a side-effect, you
can now re-open and accept an erroneously-rejected incident and CanIt will deliver the message.
• MAJOR NEW FEATURE: Compound Rules have been enhanced with additional fields and
relations, as well as a macro feature that lets you specify things like “envelope sender” in the
data box; this permits extra flexibility when creating Compound Rules.
• MAJOR NEW FEATURE (Appliance Only): If you have the log indexing component installed,
CanIt tracks how often custom rules and compound rules are hit. These statistics let you evaluate
the effectiveness of your rules and remove those that never or rarely hit.
• MINOR NEW FEATURE (Appliance Only): The log-searcher can search the “tests=X;Y;Z”
log string so you can search for specific rule hits.
• MINOR NEW FEATURE: On a per-stream basis, you can request that rate-limiting rules apply
to a stream even if mail was not forced into it by a Known Networks entry.
• MINOR NEW FEATURE (CanIt-Domain-PRO only): The force-to-stream field in Known Networks lets you specify “@@:streamname” or “realmname:@@”. In either case, ’@@’ is replaced with the realm of the envelope sender.
• IMPROVEMENT: The URL Proxy feature permits you to specify a separate template for
suspected-phishing URLs as opposed to normal URLs. You can also specify a different Base
URL for the URL Proxy page.
• IMPROVEMENT: The Pending Notification templates have additional substitution tags for
more flexible formatting of dates and times.
• IMPROVEMENT: Display of MIME-formatted messages is supported on all platforms. Appliances use fast C code to decode MIME messages; other platforms use a slower pure-PHP
library.
• IMPROVEMENT: The code to select Storage Manager nodes for writing attempts to ensure that
one copy of data is written in each geographical location if you provide location information
in the Cluster Members table. Selecting a node for reading continues to be ordered strictly by
latency.
• MINOR IMPROVEMENT: The API call for domain routing permits specifying the list of destination servers as a comma-separates string as well as an array.
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• MINOR IMPROVEMENT (Secure Messaging): Secure Messaging can be configured via the
API.
• MINOR IMPROVEMENT (Secure Messaging): You can specify a separate Base URL for the
Secure Messaging portal than for the rest of CanIt.
• MINOR IMPROVEMENT: A config.php setting permits you to prohibit the “Queue All Addresses” option for Verification Servers.
• MINOR IMPROVEMENT: Compound and Custom Rules with a score of zero are no longer
evaluated at all. If you want to make test rules that don’t materially affect the score, assign a
score of 0.001 to force the rule to be run.
• COSMETIC CHANGE: The Known Networks “Don’t Tempfail Incidents” attribute has been
renamed to the more descriptive “Friendly Host”
• BUG FIX: The cron job to expire old Bayes data now runs on all cluster members rather than
just on the database server.
• BUG FIX/IMPROVEMENT: The Custom Rule code has been overhauled to make the code
much simpler and Custom Rule evaluation faster.
• BUG FIX: If a rate-limit setting causes a rule to be created, the new rule is now entered into the
audit table and appears in “Show Changes”.
• BUG FIX: The code to test User Lookups now ignores internal records about back-end servers
that are down and always attempts to run the lookup.
• BUG FIX: If you choose to sort messages in pending notification by score, earlier versions of
CanIt could incorrectly ignore the ”Only show new incidents” flag. This has been fixed.
• BUG FIX: Sendmail accepts a RCPT command like this: RCPT To:<local@ example.com>
The space confuses CanIt’s streaming mechanism, so CanIt is now hard-coded to reject RCPT
commands with whitespace in the domain part.
• BUG FIX: (Appliance Only): Searching logs by sender/recipient was case-sensitive; this has
now been fixed to be case-insensitive.
• BUG FIX: The default DNS timeout for SPF checks has been set to a more reasonable 10
seconds instead of 120 seconds.
• BUG FIXES: Numerous cosmetic bugs were fixed.
• IMPROVEMENT (CanIt-Domain-PRO only): User-lookups can be inherited by subrealms. If
you have a number of subrealms that all use the same LDAP settings, for example, this can
greatly simplify setup and reduce data duplication.
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• CHANGE: We include a new command-line API client called “canit-api-wrapper”. We promise
that this one will last and not be deprecated, unlike the previous iterations of command-line
clients.
• POLICY CHANGE: Creating a Verification Server entry now defaults to “Queue Seen Addresses” rather than “Tempfail” if the back-end server is down.
• POLICY CHANGE: If every machine has a “location” entry in the Cluster Members Table,
CanIt attempts to use a Storage Manager node in each location first, and then any remaining
writes are done in order of measured latency.
• MINOR NEW FEATURE: You can explicitly log training links in the mail log so that you can
vote messages based on data in the logs.
• BUG FIX (Appliances Only): The log-search page could lose track of the current query. This
has been fixed.
• BUG FIX: CanIt would sometimes fail to import Custom Rules that had been exported by an
older version of CanIt. This has been fixed.
• BUG FIX: Storage Manager now implements timeouts when locking a file for append. It also
uses the TCP “keepalive” option to ensure that Storage Manager servers eventually exit if a
client machine crashes.
• BUG FIX: The URL Proxing feature could sometimes convert HTML entities to UTF-8 characters inappropriately. This has been fixed.
• BUG FIX: Perl warnings in the URL Normalizer have been fixed.
• POLICY CHANGE: SURBL rules are disabled by default since the SURBL maintainers may
require a commercial license to use their RBL. Instructions for re-enabling SURBL are included
in our dynamic ruleset; be sure you qualify for free usage or purchase a subscription before
enabling SURBL rules.
• NEW FEATURE: You can supply a list of Bayes stop-words. These are words that will be
completely ignored by Bayesian analysis. This feature is designed to exclude common nonEnglish words from Bayes in situations where much of your valid email is not in English.
• NEW FEATURE: Compound Rules, Archiver Rules and Secure Messaging Rules have built-in
tests to look for credit card numbers, Canadian social insurance numbers and US social security
numbers.
• NEW FEATURE: We make use of a collaboratively-maintained list of known phishing URLs;
our URL Proxy feature always proxies URLs on the list and also prevents users from clicking
through to them.
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• NEW FEATURE (Archiver and Secure Messaging only): When replying to a message via the
Web interface, you can now add attachments.
• POLICY CHANGE: URL proxying is enabled by default. However, on new installations we
only proxy URLs in the Known Phishing URL list.
• MAJOR IMPROVEMENT (Appliance only): Log-searching has been completely overhauled.
You can now make complex searches with AND/OR/NOT combinations. You can name
searches and save them for later reuse.
• IMPROVEMENT: The code to import/export rules and settings from streams was completely
overhauled. You can now import and export Quarantine Settings in addition to most types of
rules.
• MINOR NEW FEATURE: Per-realm theme customizations now also apply to the Secure Messaging interface.
• MINOR NEW FEATURE: Unofficial/contributed script canit-analyze-rule-hits.pl allows you to
analyze the hit rate of custom and compound rules.
• MINOR IMPROVEMENT: Audit trail (“Show Changes”) data persists for two years by default
rather than the previous default of 90 days. You can also configure it to persist for up to 10 000
days.
• MINOR IMPROVEMENT: Whenever we log a “PhishingAddress” rule hit, we now also log
the score of the hit.
• BUG FIX: If a domain completely lacks MX records, the “Bogus MX” test uses the A record(s),
if any.
• BUG FIX: Several PHP warnings were eliminated.
• BUG FIX (CanIt-Domain-PRO only): The site administrator can now delete out-of-realm entries in the Valid Recipients Table.
• BUG FIX: The “Report Time Span” on Classification reports spans the time for which data is
available rather than just the time from the first to the last event actually included in the report.
This gives a more accurate picture.
• BUG FIX: An edge-case could occur in which a pending incident was created, but CanIt did not
realize it needed to send a Pending Notification. This has been fixed.
• BUG FIX (Appliance only): If a message is accepted or rejected directly by Sendmail without
any CanIt log lines, the log parser assigns a resolution of “accepted” or “rejected” based on
Sendmail’s delivery status code.
• BUG FIX (Secure Messaging only): If a user clicks on the registration link but has already
registered for a Secure Messaging account, CanIt now presents the normal login form.
• BUG FIX (Secure Messaging only): An extremely rare edge-case in which CanIt could create
an invalid link for a secure message has been fixed.
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• IMPORTANT SECURITY FIX: A cross-site scripting vulnerability in the URL Proxy page has
been fixed. *** ALL 9.1.2 USERS SHOULD UPGRADE ***
• SECURITY IMPROVEMENT: If you are running PHP 5.2.0 or newer, CanIt sets the
“HttpOnly” flag on its cookie, which may help mitigate cross-site scripting attacks.
• NEW FEATURE (CanIt-Domain-PRO only): The “force to stream” feature lets you specify a
stream of the form: “realmname:@@”. The “@@” part is replaced with the realm of the envelope *sender* address. This can be used (for example) to implement per-domain disclaimers on
outbound mail.
• IMPROVEMENT: On Debian Squeeze and Wheezy appliances, and on all platforms where the
“lsar” program is available, CanIt can look inside many different types of archives for filename
extensions. The list includes ZIP, RAR, and tar files. Previously, CanIt could only look inside
ZIP files.
• BUG FIX (CanIt Appliance only): When canit-setup-appliance enumerated available time
zones, it would ignore ones that were symbolic links. This has been fixed.
• BUG FIX: LDAP lookups now have an overall timeout applied. Previously, if the connection
succeeded but the LDAP server never responded, the scanning process would hang for a very
long time.
• BUG FIX (CanIt Archiver only): The archive importer program would fail unless you specified
the –force realm and –force stream flags. This has been fixed.
• BUG FIX (Secure Messaging only): When fetching a secure message, the fetch would be logged
several times. This has been fixed so each fetch is logged only once.
• BUG FIX: CanIt uses a UTF-8-aware word-wrapping function. This should avoid display problems in the quarantine display for messages with very long subject lines.
• BUG FIX: The URL Proxy feature handles URLs with trailing punctuation in plain-text messages in a way that preserves the original intent better.
• BUG FIX: If you add a custom header to all messages through CanIt, then CanIt replaces any
existing custom header with the same name rather than adding a second custom header.
• BUG FIX: The URL Proxy administration page would fail if you switched to the “*” pseudostream; this has been fixed.
• BUG FIX: 9.1.2 would fail on PHP installations that lacked the mbstring extension. This has
been fixed so that CanIt continues to work, albeit in a somewhat degraded fashion.
• BUG FIX: The URL Proxy code could fail on Red Hat Enterprise Linux 5 because it used PHP
features lacking on that system. This has been fixed.
• BUG FIX: If the X-CanIt-Geo: header or a CanIt custom header has a character with the high-bit
set, the header was not properly MIME-encoded. This has been fixed.
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• MINOR BUG FIX: On source and Red Hat installations, permissions were loosened somewhat
so the URL Proxy feature can use the geolocation database.
• MINOR BUG FIX: Several PHP warnings have been suppressed.
• COSMETIC FIX: Translation templates that are no longer used have been removed from the
Setup : Templates page.
• COSMETIC FIX: The order of options to dispose of messages in the quarantine display has
been changed to group all “accept-type” options together followed by all “reject-type” options.
• MAJOR NEW FEATURE: CanIt can wrap URLs in email messages to take users to a landing
page warning them not to supply sensitive information. They can then click on a link to go to the
original URL. This may help reduce the success rate of phishing attacks. See “URL Proxying”
in the Administration Guide.
• IMPROVEMENT: The Pending Notification email message can be templated to a larger degree,
permitting larger changes to the appearance and content than was possible before.
• MINOR IMPROVEMENT: A preference controls whether CanIt displays a formatted or unformatted message by default when previewing a quarantined message.
• MINOR IMPROVEMENT: SPF and DKIM rules now have a “Comment” field.
• MINOR IMPROVEMENT: Choosing a “Vertically-Compact Trap Display” turns off some more
unnecessary line-breaking.
• BUG FIX: Permissions have been fixed so that a read-only user cannot create Periodic Reports.
• BUG FIX: The Bayes tokenizer now ignores tokens shorter than 3 characters except for ideographic character sets like CJK Unified Ideographs.
• BUG FIX: Previously, CanIt would round SpamAssassin scores to one decimal place. This was
a bit too coarse; we now keep two decimal places of precision.
• BUG FIX (Appliance only): Fix a bug in the code that enumerated possible time zones.
• BUG FIX: If you specify a custom header and the header already exists on the incoming email,
replace the header rather than adding a second one.
• BUG FIX: Use UTF-8-safe code to wrap the subject display in the Quarantine display.
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• MAJOR IMPROVEMENT: If CanIt has a complete message held locally, then the message
preview in the quarantine display formats the MIME message correctly instead of showing raw
MIME. NOTE: This feature is available only on our Debian-based appliances and on Hosted
CanIt.
• IMPROVEMENT: The RSS feed includes a link to whitelist the sender of a trapped incident.
• MINOR IMPROVEMENT: The rendering of MIME messages within the Web interface has
been improved.
• IMPROVEMENT: The two flavors of relay address have been renamed to “Connecting Relay
Address” and “Sending Relay Address” and the definitions in the manual have been clarified:
The Connecting Relay is the other end of the SMTP connection, while the Sending Relay is
possibly parsed out of the Received: headers.
• IMPROVEMENT (Secure Messaging add-on): CanIt displays both an INBOX (for received
secure messages) and a Sent box (for sent ones.)
• MINOR NEW FEATURE: You can configure the Administration : Show Queue display to hide
message subjects by default, revealing them only upon clicking a link.
• POLICY CHANGE: IP-based rate-limiting rules are applied first based on the sending relay,
and if no rule is found, then based on the connecting relay.
• POLICY CHANGE: When an incident is released, we hold on to any locally-held message
rather than deleting it immediately. This permits the display of a correctly-formatted MIME
message in the quarantine display.
• BUG FIX (Secure Messaging add-on): The encryption module could deadlock on very large
messages. This has been fixed.
• BUG FIX: If an incident is created in tag-only mode, then the log-indexer links to the incident
page when displaying the relevant log lines.
• BUG FIX: The “Skip SPF Checks” Known-Networks flag now applies to both the Sending
Relay and the Connecting Relay.
• BUG FIX: The Web interface could fail on very old versions of PostgreSQL that lack the “standard conforming strings” parameter. This has been fixed.
• BUG FIX: Setup : Templates includes a template for translating “Country”
• BUG FIX (CanIt-Domain-PRO only): The Stream Count by Realm report could fail on older
versions of PostgreSQL. This has been fixed.
• BUG FIX: A bug in the Autotask billing module could cause the cron job to generate gigabytes
of warning messages. This has been fixed.
• BUG FIX: Setup : Domain Overview now shows all domains that have been set up within a
realm, even if they lack explicit realm mappings.
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• MAJOR NEW FEATURE: A Secure Messaging add-on is available. This lets you create policies for storing mail locally rather than delivering it, and requiring recipients to log on over
HTTPS to securely view their messages.
• NEW FEATURE (Hosted CanIt and CanIt-Domain-PRO only): Hosted CanIt and CanItDomain-PRO can integrate with Autotask(TM) to automate monthly billing for anti-spam services.
• NEW FEATURE: You can override scores for SpamAssassin rules. This can be done on a
per-stream basis and obeys the normal stream inheritance rules.
• IMPROVEMENT: The “xauth” API call takes an optional “redirect” parameter to automatically
place a user in an interior CanIt page after single sign-on.
• IMPROVEMENT: The RSS feed feature has been improved, making it much more useful for
keeping an eye on your quarantine.
• POLICY CHANGE: Set default Storage Manager client operation timeout to 90 seconds instead
of 20. 20 was too short for installations with slow networks and large messages.
• PERFORMANCE IMPROVEMENT (Archiver only): The cron job that expires old archived
mail does it in smaller chunks each night to avoid a very long-running cron job.
• PERFORMANCE IMPROVEMENT: The Storage Manager client/server protocol contains a
mechanism to reduce network traffic when archiving many copies of the same message.
• DOCUMENTATION IMPROVEMENT: Clarify the distinction between “Connecting Relay”
and “Sending Relay” in the context of Known Networks flag “Parse Received Headers”.
• BUG FIX: Make Known Networks “Skip SPF Checks” flag apply to both Connecting Relay
and Sending Relay.
• BUG FIX: You can toggle the “Is root?” flag for CanIt users from within the Web interface.
Before, you had to delete and recreate the user.
• BUG FIX: Character-set decoding problems in the message preview have been fixed.
• BUG FIX: The Web interface could fail with newer versions of PostgreSQL if standard conforming strings was enabled. This has been fixed.
• BUG FIX: If you have a new-enough version of PHP, the LDAP timeout setting is honored for
authentication attempts. This requires PHP 5.3 or later.
• BUG FIX: If CanIt creates an incident for a tagged message, the log indexer now links to the
incident details page.
• BUG FIX: If you used Parse Received Headers with outbound rate-limiting, CanIt could use the
wrong IP address to look up rate-limiting rules. This has been fixed.
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• NEW FEATURE: On a per-stream basis, the entries in the Pending Notification email can optionally be sorted by score ascending rather than date descending.
• NEW FEATURE: All Periodic Reports produce CSV attachments for each chart as well as PDF.
This permits the report data to be imported into a spreadsheet and manipulated as required.
• NEW FEATURE: You can create periodic reports showing email address usage.
• MINOR IMPROVEMENT: LDAP user-lookups can force the use of SSLv3 when streaming.
• BUG FIX: The German language localization was completely broken; it is now fixed.
• BUG FIX: Localized column names in reports sometimes had entities double-escaped resulting
in things like “ö” appearing instead of the proper character.
• BUG FIX: Some PHP “Strict Standards” warnings were fixed.
• BUG FIX: The wrong permission was being used to control access to the “Statistics” menu
entry. This has been fixed.
• BUG FIX: On busy systems, the default “backlog” parameter to listen() for the Storage Manager
daemon may result in errors writing to the storage manager. We have increased the default
backlog from 5 to 16 and made it configurable in canit.conf
• BUG FIX: If you have enabled the global setting ”Store both raw and decoded messages in incident database” and are using Storage Manager, certain messages could cause protocol violations
with Storage Manager and cause mail to be tempfailed. If your mail logs show many instances
of “PROTOCOL ERROR” from canit-storage-manager, you must upgrade to 9.0.13.
• NEW FEATURE (CanIt-Domain-PRO only): There is a new API call that permits you to rename a realm.
• NEW FEATURE: The training link template now lets you add templates for whitelisting/blacklisting senders. Note, however, that whitelisting or blacklisting a sender always requires authentication even if normal voting does not.
• NEW FEATURE (CanIt-Domain-PRO only): The site administrator can completely suspend
service to a realm. This blocks all login attempts and rejects all mail for the realm.
• NEW FEATURE: A new “xauth” API call permits you to create single sign-on links from within
other Web portals.
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• NEW FEATURE: In addition to per-sender and per-IP rate-limits, you can also apply perdomain rate-limits to outbound mail.
• NEW FEATURE (Archiver only): There are now API calls to configure archiving.
• UPDATE: ClamAV has been updated to version 0.98
• DEPRECATIONS: Debian 4.0 (“etch”) is no longer supported. Debian 5.0 (“lenny”) is now
deprecated.
• MINOR CHANGE: The GET /api/2.0/info API call includes more information.
• MINOR BUG FIX: The bulk-entry page would not permit domain-rule entries of the form:
.example.com. This has been fixed.
• BUG FIX: LDAP user-lookups would fail mysteriously if an LDAP URL was entered in uppercase: LDAPS://SERVER.EXAMPLE.COM. This has been fixed.
• BUG FIX: CanIt’s “alias” mechanism was case-sensitive. This has been fixed.
• BUG FIX: Several PHP warnings (Strict Mode warnings) have been fixed.
• BUG FIX: The X-Spam-Flag: YES header is correctly added if a message is tagged because of
a filename extension rule.
• POLICY CHANGE: If you make a specific SPF rule for a domain “example.com” and set the
“fail” and “softfail” scores to zero, then CanIt does respect domain and sender whitelists for that
domain, even if SPF fails or softfails.
• BUG FIX: Custom rules and compound rules still did not work correctly for non-latin characters
and certain regular expressions in some cases. This has been fixed.
• BUG FIX (Archiver only): If a message fails to be archived, it is tempfailed so there’s no
possibility of losing messages.
• NEW FEATURE: Add a $Config setting to hide message bodies from users if they are not in
their home stream. This can be used to limit what helpdesk users can see in others’ streams.
• COSMETIC IMPROVEMENT: The License Key page makes it much clearer when a new license key is accepted.
• IMPROVEMENT: Anywhere CanIt asks for an email address to which to send email, you can
supply a comma-separated list of addresses and the mail will go to all of them.
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• PERFORMANCE IMPROVEMENT: If a recipient is specified in a log-search, CanIt automatically restricts the stream (and realm, in Domain-PRO) to that of the recipient. If this is not
desired, a “contains” relation will prevent the automatic stream restriction.
• MINOR IMPROVEMENT: The page for testing LDAP lookups optionally dumps the entire
LDAP entry as LDIF for debugging purposes.
• BUG FIX: Custom rule and compound rule evaluators convert all text lines to Unicode before
applying rules. This means that custom and compound rules with non-Latin characters will now
work correctly on all messages.
• BUG FIX: If you use the “create incidents for tagged messages” feature, CanIt would show the
status as “Auto-Rejected”. That has been fixed; it now reads “Tagged”.
• BUG FIX: On recent Linux systems such as Debian 7.0, RPTN downloads would fail with an
“Unable to validate SSL certificate” error. This has been fixed.
• BUG FIX: Custom and Compound rules use Perl rather than PHP to validate regular expressions, ensuring that the full power of Perl regexes is available.
• BUG FIX: The “See Active Queries” link on the Cluster Management page connects as the
PostgreSQL super-user to show more information about active queries.
• BUG FIX: A rare edge-case interaction between an unfrozen incident and a whitelist could
allow large spam runs to leak through. This has been fixed.
• BUG FIX: CanIt’s SummarizeStatistics task in 9.0.9 was broken on older versions of Perl
(5.8.8); this has been fixed.
• BUG FIX: The CanIt Failover SNMP module has been made more forgiving so as not to raise
spurious alerts about failover problems.
• BUG FIX (CanIt-Archiver): For journalled messages, CanIt adds all envelope recipients to the
list of addresses for archiving.
• NEW FEATURE: (CanIt-Appliance only): CanIt can be configured to send an email notification
if mail for a given domain starts to queue.
• MINOR IMPROVEMENT (CanIt-Domain-PRO only): The /provision and /domain route API
calls take extra parameters to configure queued-mail notification (the feature mentioned above.)
• MINOR IMPROVEMENT (CanIt-Domain-PRO only): The address-count-by-realm report now
also reports the stream count by realm.
• MINOR IMPROVEMENT: A new report charts the number of addresses and streams seen over
time.
249
• MINOR IMPROVEMENT: The color-selection code has been tweaked so that graphical reports
have more pleasing colors.
• MINOR IMPROVEMENT (CanIt-Appliance only): The System Check task that checks for
sufficient free disk space now also checks for sufficient free inodes.
• POLICY CHANGE: In certain specific situations, a tempfail from a verification server is converted to a permanent reject. This occurs if the SMTP response from the back-end verification
server ends with either of the following:
Recipient address rejected: User unknown in local recipient table Mailbox size limit exceeded
• BUG FIX: The “restart-gracefully” and “stop-gracefully” arguments to /etc/init.d/canit-system
did not correctly stop the CanIt Daemon (canitd) process. This has been fixed.
• BUG FIX: (Archiver only): Archiving rules are now correctly applied to journalled messages.
(Before, journalled messages were archived unconditionally.)
• BUG FIX: The code that counts the number of email addresses seen now correctly removes
BATV tags and sendmail “plus-hack” suffixes to avoid multiply-counting the same email address.
• BUG FIX: Domain-routing entries that start with a dot could cause the ticker system-check task
to die. This has been fixed.
• BUG FIX: Theme customization would not work on versions of PostgreSQL older than 8.2; this
has been fixed.
• BUG FIX (CanIt-Domain-PRO only): The system prevents you from deleting a realm-mapping
if a domain-routing entry exists for the domain.
• UPGRADES: Many included Perl modules have been updated to more recent versions.
• EXPERIMENTAL: We now have Debian 7 “Wheezy” packages and ISO images. These are
still considered experimental.
• NEW FEATURE: IMAP and POP3 user-lookups can rewrite the login name to a stream using
a Rewrite Expression.
• NEW FEATURE: CanIt stores and displays the “full name” from the From: header in the quarantine display and the archive display (archiver add-on only.)
• POLICY CHANGE: By default, normal users cannot reopen incidents. Only administrators
can.
• MINOR IMPROVEMENT (Appliances Only): The log search feature allows you to search by
minimum/maximum score, “reason” and “detail” fields. (This applies only to log lines indexed
after the 9.0.8 upgrade.)
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• MINOR IMPROVEMENT: The Web interface can be put into “Maintenance Mode”. This prevents users from doing anything and displays a maintenance notice of your choice.
• MINOR IMPROVEMENT: More theme elements are customizable.
• MINOR IMPROVEMENT: You can choose to place the action buttons on the left or the right
in the quarantine display.
• MINOR IMPROVEMENT: A “danger” sign warns of hazardous attachments like EXE files to
make it clear that a quarantined message might be malware.
• MINOR IMPROVEMENT: The replacement sequence “%=X” is replaced with the number of
X’s equal to the spam score, where X can be any character except “%”.
• BUG FIX: Fixed race condition that could result in tempfail when attempting to create an incident.
• BUG FIX: Fixed various edge-cases in the ”Create incidents for tagged messages” feature.
• MAJOR NEW FEATURE: If CanIt has enough local Bayes statistics for a given token, it can use
local statistics in preference to inherited statistics and RPTN. This means that CanIt responds
more quickly to training. Our experience with this feature is limited, so by default it is disabled.
Turn it on under Preferences : Quarantine Settings by setting S-2410 to “Yes”. You may notice
higher false-positives for a while until sufficient local training has been created.
• MINOR IMPROVEMENT: You can use the %{empty} tag in tag-only mode to prevent the
subject from being tagged (but the X-Spam-Flag: YES header is still added if appropriate.)
• UPGRADE: ClamAV has been upgraded from 0.97.7 to 0.97.8.
• PERFORMANCE IMPROVEMENT: If you are using Storage Manager, the code that creates
an incident keeps a database transaction open for less time than before.
• BUG FIX: If you create incidents even in tag-only mode, CanIt could end up auto-rejecting the
second and subsequent copies of the same email. This has been fixed.
• BUG FIX (CanIt-Domain-PRO appliance only): Messages that were forced into a stream could
have their log lines indexed in the wrong realm. This has been fixed.
• BUG FIX: Several deprecated Perl constructs have been fixed.
• BUG FIX (CanIt-Domain-PRO only): In a highly-unlikely edge case, CanIt-Domain-PRO could
use an incorrect user-lookup for a domain. This has been fixed.
• BUG FIX: The Regular Expression web page uses a Perl helper script to test the regular expressions, which gives more accurate results than doing it in PHP.
• BUG FIX: Many PHP constructs that yielded errors in PHP 5.4 have been fixed.
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• BUG FIX: If a realm has domain-related information like domain mappings or authentication
mappings, the GUI and API prevent remapping the domain unless the related mappings are first
deleted.
• POLICY CHANGE: Doing a quarantine search by sender searches only the header sender; the
query to search envelope senders could be pathologically slow in some situations.
• MINOR NEW FEATURE: The Cluster Management page lets the site administrator display a
snapshot of active database queries.
• MINOR IMPROVEMENT: A sample “site failover” script has been included that notifies administrators of an impending notification and lets them either force or cancel failover.
• PERFORMANCE IMPROVEMENT (CanIt-Domain-PRO only): The query to locate an existing incident based on its hash has been made faster.
• BUG FIX: The RSS Feed menu item would be displayed even if a user lacked RSS permission
(though the menu entry would display Permission Denied if clicked.) Now the menu entry is
correctly hidden.
• BUG FIX: In certain circumstances, CanIt could fail to send notifications to people with pending
messages in the quarantine. This bug was introduced in release 9.0.1, so anyone running 9.0.1
through 9.0.5 should upgrade.
• NEW FEATURE: In a CanIt cluster, cluster members can be grouped by location. When CanIt
synchronizes Bayes data across a cluster, it attempts to minimize bandwidth used to copy files
from one location to another. This improves performance if your cluster has several groups of
machines connected by relatively low-bandwidth links.
• NEW PERMISSION (CanIt-Domain-PRO only): You can disable the ability of realm administrators to see/edit User Lookups. This may be important if they contain passwords that should
not be revealed to subrealm administrators.
• NEW REPORTS: CanIt now features a report showing the top Operating Systems seen for
recent messages. This works only if your platform supports the Passive OS Fingerprinting
module.
• POLICY CHANGE: In tag-only mode, if a message is tagged as spam, the headers “Precedence:
bulk”, “X-Auto-Response-Suppress: All” and “Auto-Submitted: x-no-autoresponse-please” are
added. This is designed to prevent out-of-office software from auto-responding to tagged mail.
• PERFORMANCE IMPROVEMENT: Failover initialization performs less data copying and
uses less disk space than before.
252
• BUG FIX: The failover system now operates correctly on databases that use multiple tablespaces.
• BUG FIX (CanIt-Domain-PRO only): The system now prevents you from deleting a realmmapping if domain-related information such as Verification Servers, Domain Mappings or Authentication Mappings exist for domains within the realm mapping.
• BUG FIX: The system now prevents you from marking “default” as a special stream.
• BUG FIX: A bug that prevented theme customization in themes with more than one customizable image has been fixed.
• BUG FIX: If a user has access to all streams (by virtue of having “*” in the Accessible Streams
list), stream auto-complete now works.
• BUG FIX: During outbound rate-limiting, CanIt would sometimes send multiple notifications
due to a race condition. Now it only sends exactly one notification.
• NEW FEATURE: The RPM and Appliance versions of CanIt include passive OS fingerprinting
which attempts to guess the operating system and link type of the SMTP client. The results are
tokenized for Bayes and can be used in Compound Rules.
• NEW FEATURE: The API permits a POST to /rules to bulk-create rules. This can be substantially faster than iterating on the client side.
• UPDATE: We ship ClamAV 0.97.7 (updated from 0.97.6)
• GUI IMPROVEMENT: The window that pops up in response to clicking on a voting link makes
it clearer that the vote has taken place and no further action is required.
• GUI IMPROVEMENT: Emblems in the Quarantine Display show SPF pass/fail/softfail results.
• IMPROVEMENT: We store and display both the first and last occurrence of an anomaly (under
Administration : Anomalies) rather than just the last occurrence.
• IMPROVEMENT: The Compound Rule compiler has been split out from the run-time evaluation of compound rules to save memory.
• IMPROVEMENT: The internal “Circuit Breaker” code that backs off from contacting dead
servers remembers the last error message and uses it for more informative anomaly messages.
• IMPROVEMENT: The comments (if any) associated with Compound Rules and Custom Rules
are added to the spam report.
• IMPROVEMENT: Various sections of the Pending Notification have class attributes, allowing
them to be suppressed with CSS code in the template “Header for ’Webform’-style Pending
Notification”.
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• IMPROVEMENT (CanIt-Domain-PRO appliance only): The log indexer tries much harder to
determine which realm various log messages apply to, meaning realm administrators have access to more of their logs than before.
• POLICY CHANGE: The “Email Address Usage” reports only consider email addresses seen
within the last 30 days.
• POLICY CHANGE: The default timeout for LDAP lookups has been reduced from 120 seconds
to 20 seconds.
• POLICY CHANGE: Sender blacklists created in response to clicking “Blacklist Sender” in a
Pending Notification now expire after 60 days rather than persisting forever. This policy change
was made after determining that most such blacklists were not useful because they blacklisted
disposable addresses.
• POLICY CHANGE: The “Silently Discard” option for handling incidents has been removed.
In most deployment scenarios, “Reject Message” is actually the same as “Silently Discard”
anyway.
• POLICY CHANGE: The minimum counts before using Bayes data now apply to the aggregate
of all Bayes databases rather than each Bayes database individually. This makes CanIt start
using personal Bayes data much sooner than before.
• BUG FIX: An explicit “Reject” for a sender or domain now overrides a “Hold if looks like
spam” rule from a parent stream.
• BUG FIX: The Quarantine Search would fail to find messages with accented (or any non-ASCII)
characters in the subject. This has been fixed.
• BUG FIX: The Bayes @@PARENTS inheritance mechanism has been completely fixed. Before, the Web interface would display misleading information.
• BUG FIX: Minor problems with the Compound Rule entry page have been fixed. It is also now
possible to see compound rules in all streams if you switch to the “*” pseudo-stream.
• BUG FIX: The API would not permit creation of a “*” address mapping; this has been fixed.
• BUG FIX: The API would not permit a domain rule of the form “.example.com” with a leading
dot. This has been fixed.
• BUG FIX: An error in the compound rule compiler has been fixed. Upon upgrade, all compound
rules will be recompiled to ensure that the generated code is correct.
• NEW FEATURE: You can add your own custom X- header to delivered messages. The header
template includes several substitution tags that will be replaced on delivery; see the User’s Guide
for details.
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• IMPROVEMENT: The Bulk Entry rule page lets you set an expiry date on rules you enter.
• IMPROVEMENT: Compound Rules can now use the SPF and DKIM results as part of the rule.
• IMPROVEMENT (CanIt-Domain-PRO only): Under Setup : Templates in a non-base realm,
you can revert a template to its inherited value.
• IMPROVEMENT: The “Viewing Stream” display has been improved to more clearly show
stream inheritance.
• IMPROVEMENT: Pending Notifications now include the country-code of the SMTP relay and
an indication if the envelope sender differs from the From: header.
• BUG FIX: In Rules : Sender, you can select “Tempfail” in the filter action.
• BUG FIX: The “Simplified Interface” ignored any logo customization (under Setup : Theme
Customization.) This has been fixed.
• BUG FIX: In the Compound Rules editor, pressing Enter in the comment field would result in
the “Delete” button being activated instead of “Save”. This has been fixed.
• BUG FIX (CanIt-Domain-PRO only): The mechanism to propagate Bayes hand-votes up the
realm hierarchy did not work correctly. This has been fixed.
• POLICY CHANGE: Due to significant demand, we have reinstated the “Clickable Webform”
pending notification type.
• POLICY CHANGE: You can now select whether Pending Notification emails only notify about
new incidents created since the previous notification (9.0.1 behavior) or all pending incidents
(pre-9.0.1 behavior.) The default is to notify only about new incidents since the previous notification.
• NEW FEATURE: You can add arbitrary CSS when you customize a theme, allowing for very
fine control over the theme’s appearance.
• MINOR NEW FEATURE (CanIt-Domain-PRO only): You can specify @@PARENTSn (when
n is a decimal number) to inherit Bayes training from a limited number of ancestor streams.
• BUG FIX: The @@PARENTS Bayes-training inheritance setting was not accepted by the GUI.
• POLICY CHANGE: Please read the CanIt license (found in an appendix in the Administration
Guide and User’s Guide) for a disclaimer about time-critical mass-mailings.
255
• POLICY CHANGE (CanIt-Domain-PRO only): Realm administrators can delete realm mappings they own, effectively deprovisioning a domain.
• POLICY CHANGE: The “Clickable Webform” pending notification type has been removed. It
didn’t work in most email readers anyway.
• POLICY CHANGE: Pending Notification emails now only include any new incidents created
since the previous notification.
• MAJOR NEW FEATURE: You can create compound custom rules. These let you combine
conditions with boolean operators. Because of the power of these rules, they are available by
default only to administrators, although end-users can be granted permission to create them.
• MAJOR NEW FEATURE: Rate-limiting rules are much more versatile, permitting per-sender
settings and including the ability to hold all mail from a rate-limited sender.
• NEW FEATURE (CanIt-Domain-PRO only): A new “provision” API call has been added to
simplify provisioning new domains. The site administrator can grant provision permission to
trusted realm administrators.
• NEW FEATURE: An aliasing feature has been added; this causes CanIt to actually rewrite
recipient addresses (as opposed to simply streaming them into one stream but not rewriting the
destination address.)
• NEW FEATURE (Appliance only): CanIt allows administrators to temporarily pause delivery
to specific domains. This can be useful if a back-end mail server is undergoing scheduled
maintenance.
• NEW FEATURE: CanIt can cache login credentials so that if a back-end IMAP, POP3 or LDAP
server goes down, users can still log in (providing they have successfully logged in recently.)
• NEW FEATURE: You can request CanIt to create incidents even in tag-only mode. This may
make it easier to determine why a message was tagged.
• NEW FEATURE: The “Strip Attachment” feature now lets you specify that administrative permission is required to release attachments that were stripped and held on the server.
• NEW FEATURE: The “See Mail Queue” page lets you summarize queued messages by destination domain.
• NEW FEATURE: Hand-votes in a stream are also recorded in the “default” stream (and in
the case of CanIt-Domain-PRO, the “default” stream of all ancestor realms.) This effectively
creates site-wide Bayes databases which can be used by specifying that streams should use
training from @@PARENTS (see manual for details.)
• NEW FEATURE (Archiver only): You can create rules that specify whether or not to archive
messages. This lets you avoid archiving machine-generated notifications or other messages that
you don’t want archived.
• NEW API CALL: GET /api/2.0/address to stream/[email protected] returns the stream to
which “[email protected]” would be mapped.
256
• GUI IMPROVEMENT: Several icons in the Quarantine Overview page display additional information about incidents such as SPF fail/softfail and important notes about the incident.
• IMPROVEMENT: Several new SNMP variables to monitor the health of the CanIt server are
now available: Total number of system checks, number of failed system checks, and total number of anomalies detected.
• MAJOR IMPROVEMENT: RPTN reporting has been revamped to try to preserve as many
hand-votes as possible rather than dropping excessive votes.
• MAJOR IMPROVEMENT: CanIt detects dead back-end servers and refrains from using them
for a short period of time. This can help mitigate load problems if back-end servers disappear
off the network.
• CHANGE: The notification setting ”Add ’Blacklist Sender/Whitelist Sender’ Links to HTML
Notification” has been split into two independent settings (one for adding whitelist links and
another for adding blacklist links.) On upgrade, the existing setting is migrated to both the “Add
whitelist links” setting and the “Add blacklist links” setting.
• MINOR NEW FEATURE: A “Domain Overview” page summarizes important per-domain settings and is useful for troubleshooting.
• SECURITY FEATURE: You can configure the CanIt web interface to lock sessions to a single
IP address or a small range of IP addresses. This can help thwart session-hijacking attacks.
• GUI IMPROVEMENT: The Known Networks page has a filter box that lets you reduce clutter
if you have many Known Networks entries.
• MINOR GUI IMPROVEMENT: “Alternate Addresses” has been renamed to ”My Addresses”
• MINOR GUI IMPROVEMENT: “Stream Settings” has been renamed to “Quarantine Settings”
• MINOR GUI IMPROVEMENT: “Address Mappings” has been renamed to “Address-to-Stream
Mappings”
• MINOR IMPROVEMENT: The LDAP user-lookup wizard now has pre-canned settings for
allowing users to log on with their email address or their Active Directory username.
• MINOR IMPROVEMENT: You can decide whether to ignore whitelists for SPF “fail” or “softfail” with two separate settings instead of one setting that applied to both fail and softfail.
• MINOR NEW FEATURE: The LDAP user-lookup code can help determine the form of the
Active Directory Bind DN setting. This makes setting up Active Directory much easier.
• MINOR IMPROVEMENT: Weekends are shaded on most reports in the Web interface.
• MINOR IMPROVEMENT: An emergency mechanism to disable theme customization has been
added to recover from customization mistakes that make the GUI unreadable.
• MINOR IMPROVEMENT: The Perl CanIt::API::Client module has a get last value() method;
see the man page for details.
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• BUG FIX: Searching the trap used case-sensitive matching for “is” relationships, which could
yield incorrect search results. This has been fixed.
• BUG FIX: The %u and %d sequences in LDAP searches did not work for authentication. This
has been fixed.
• BUG FIX: CanIt would fail to compile with FreeBSD’s make program. This has been fixed.
• BUG FIX: The Storage Manager creates a lock file to ensure that there will never be two background pruning processes running at the same time. This would never have caused an error, but
did cause excessive disk I/O.
• BUG FIX: The canit-failover-setup.pl would create invalid authorized keys files. This has been
fixed.
• BUG FIX: A rare edge-case could make data expire out of Storage Manager before it expired
out of the database, causing message retrieval to fail. This has been fixed.
• BUG FIX: A forced-to-stream incident could be re-trapped in a different stream after it is released. This has been fixed.
• BUG FIX (Appliances only): The log-indexer did not correctly index all recipients if a line was
logged with more than one recipient. This has been fixed.
• BUG FIX (Archiver only): A message with a missing charset=xxx parameter could be displayed
incorrectly. This has been fixed.
• NEW FEATURE: CanIt sets the “canit user” note for Apache. You can use this to log CanIt
users to your Apache log with the log format sequence %{canit user}n in the LogFormat directive. On our Debian-based appliances, we adjust the Apache configuration file to do this.
• NEW FEATURE: CanIt’s RP-Web theme features a “Mobile” view optimized for mobile devices. This is still considered experimental; feedback is welcomed.
• NEW FEATURE: The nightly Storage Manager maintenance task is extremely I/O intensive.
You can set a configuration setting in canit.conf to have Storage Manager limit its use of disk
bandwidth (at the expense of taking longer to run the nightly maintenance task.)
• NEW FEATURE: The failover system supports Streaming Replication on versions of Postgresql
>= 9.0. See the Cluster Guide for details.
• MINOR NEW FEATURE (Archiver): A new “to or from” search criterion has been added as a
convenience. (It saves entering two separate criteria.)
• PERFORMANCE IMPROVEMENT: You can parallelize the releasing and remailing of quarantined messages. See the Administration Guide for details.
258
• IMPROVEMENT: Storage Manager uses fewer levels of subdirectories for storing data. This
should reduce inode consumption and slightly improve performance.
• MINOR IMPROVEMENT: If you view the mail queue sorted by domain, CanIt displays the
count of queued messages for each domain.
• MINOR IMPROVEMENT: The “Automatically Populate Notification Address” setting is
shown under Preferences : Notifications to administrators in the default stream.
• BUG FIX: CanIt’s notification messages could not handle subjects or From: headers with nonASCII characters. This has been fixed; CanIt can handle any UTF-8 character sequence now.
• BUG FIX: In older versions, it was not possible to create a Rewrite User-Lookup using the API.
• MAJOR NEW FEATURE: The Web interface colors and logos can be themed from within the
Web interface itself. In CanIt-Domain-PRO, realm administrators can adjust the colors and
logos seen by their realms and subrealms.
• PERFORMANCE IMPROVEMENT: The nightly cron job adds additional indexes to the log
indexes, making it faster to search by subject, sender or message-ID.
• IMPROVEMENT: Additional helper scripts make setting up failover and recovering after a
failover much easier and less error-prone.
• IMPROVEMENT: You can reset stream-setting inheritance on a per-setting basis. Before, you
could only reset it for all settings in a stream at once.
• IMPROVEMENT: All of the manuals are now available as online HTML as well as PDF.
• IMPROVEMENT: Various tests (such as Blacklisted Recipients and Verification Servers) log
more details about why a recipient address is rejected, making it easier to diagnose delivery
problems.
• MINOR NEW FEATURE: You can reset open incidents to “Pending” if you make a mistake
and want more time to consider how to dispose of an incident.
• POLICY CHANGE: New installations receive a sensible default SPF rule. On upgrade, old
installations will receive the same rule if they currently lack a default SPF rule.
• POLICY CHANGE: The maximum size of messages to scan for spam has been increased from
150kB to 1MB. There are some large spams out there...
• POLICY CHANGE: The “Catch Rate” slider has been removed from the Integrated Interface.
It was not useful and could be misleading.
• BUG FIX (CanIt-Domain-PRO only): The “Daily Mail by Realm” background report could
improperly leak cross-realm information; this has been fixed.
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• BUG FIX: The failover code that makes a base backup could fail if the initial rsync took a very
long time. This has been fixed.
• BUG FIX: A very rare edge-case problem with parsing received headers and avoiding whitelists
on SPF failure has been fixed.
• BUG FIX: More cron-job failures raise a system check warning. In the past, some logged errors
but were otherwise silent.
• BUG FIX: Add-on product keys are checked for expiry and used to raise system check warnings.
• BUG FIX: Code that depended on a newer version of PHP than ships with Red Hat has been
fixed.
• BUG FIX: If a Bayes signature has expired, the Vote page provides a more useful error message.
• BUG FIX: The canit-api-client tool did not accept the –port command for “domain route update”. NOTE: You need to run “canit-api-client introspection clear” after upgrading for the
change to take effect.
• IMPROVEMENT: If you use CanIt’s web interface over HTTPS, the CANIT cookie has the
“secure” attribute set.
• MINOR NEW FEATURE: The startup script /etc/init.d/canit-system can stop CanIt “gracefully”. This means that it waits for any processes doing critical work that should not be interrupted to exit on their own rather than forcibly killing them.
• MINOR NEW FEATURE: A new canit.conf setting allows you to have all MIMEDefang files
and sockets be group-accessible.
• MINOR NEW FEATURE: The time-span over which to track email addresses that have been
seen is configurable (rather than being hard-coded at 61 days.)
• MINOR IMPROVEMENT: The SMTP reply generated when a message scores over the autoreject-and-do-not-create-incident threshold is now templatable. (It used to be hard-coded.)
• POLICY CHANGE: CanIt-generated notices use the template “Source E-Mail address of CanIt
notifications” as the envelope header instead of <>. To go back to the old behaviour, set the
template to “<>”.
• POLICY CHANGE: Subdomain-expansion for DKIM and SPF rules has changed. Check the
User’s Guide for details.
Please *carefully* read the SPF and DKIM sections of the User’s Guide to see how subdomain
expansion works in this release.
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• POLICY CHANGE: The thresholds in the failover SNMP module have been made more realistic... the old values would often trigger false alerts about problems with failover.
• PERFORMANCE IMPROVEMENT: You can parallelize sending of Pending Notifications. See
the Administration Guide for details.
• PERFORMANCE IMPROVEMENT: The nightly check to look for domains that don’t validate
recipients can be run in parallel. See the Administration Guide for details.
• PERFORMANCE IMPROVEMENT: The code to check for an existing incident has a
workaround for a potentially-poor PostgreSQL query plan.
• API IMPROVEMENT: The API call: GET /api/2.0/realm/@@/stream/STREAMNAME function now includes an “active” member in the returned hash. This is set to 1 if the stream is in
the Active Streams list and 0 otherwise.
• BUG FIX: The feature “Insert Streamed Mail Directly Into Sendmail Queue” did not lock queue
files correctly, which could lead to damaged mail. This bug has been fixed and the feature is
now safe to use.
• BUG FIX: If the backup database server uses pgbouncer, failover could fail. This has been
fixed.
• BUG FIX (Debian appliances only): A typo that broke auto-updates has been fixed.
• BUG FIX: After adding or deleting a known network, the known networks page would sometimes display incorrect information. This has been fixed.
• BUG FIX: The documentation notes (and the GUI enforces) that the ticker host must also be an
inbound scanner.
• BUG FIX: The Permissions system did not correctly restrict viewing of the Preferences : Notifications page. This has been fixed.
• MAJOR CHANGE (Appliance Only): The log-indexing feature now uses PostgreSQL instead
of Xapian. Also, the log-searching API calls have changed; be sure to read the API guide
carefully.
After you upgrade from 8.1.0 to 8.2.0, all your logs will be re-indexed, which may be slow. If
you run a busy CanIt system that uses log-indexing, please contact Roaring Penguin support
before upgrading to 8.2.0 so we may plan capacity for the log-indexer.
• IMPROVEMENT: On our Debian appliances, we have added a script that makes it easier to set
up database failover. This script eliminates many error-prone and tedious configuration steps.
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• GUI CHANGE: We have revamped the look of CanIt with a new “RP-Web” theme, which is
now the default. You can always change back to the previous “Postmodern” theme if you prefer
it.
• NEW FEATURE (Appliance Only): You can specify a non-standard port (ie, other than 25) for
mail routing.
• NEW FEATURE: The IMAP, POP3 and LDAP user-lookups optionally allow you to force the
username to lower-case.
• NEW FEATURE: Administrators (and realm administrators in CanIt-Domain-PRO) can switch
users to any other user. This allows them to see the interface exactly as it would be seen by
other users.
• NEW FEATURE: You can ask not to be notified of pending messages that score above a specified threshold. This can reduce the size of notification messages by not notifying you of obvious
spam.
• DOCUMENTATION IMPROVEMENT: The online manuals have several embedded tutorial
videos.
• IMPROVEMENT: A couple more standard auto-replies are recognized to avoid autowhitelisting on an auto-reply.
• IMPROVEMENT (Appliance Only): Several more types of log lines are recognized and given
explanations.
• POLICY CHANGE: An SPF, DKIM or Domain rule on “example.com” would *also* apply to
all subdomains of “example.com”. This is no longer the case. However, you can make a rule
on “.example.com” (note the leading dot) that applies only to all subdomains of example.com.
Consult the manuals for details.
• POLICY CHANGE: The “Mismatch Rule” feature was removed. It was easily abused and has
been obsoleted by SPF.
• POLICY CHANGE: We no longer ignore whitelists if the Header From: sender would fail SPF
tests. The previous policy broke many mailing lists.
• POLICY CHANGE: The Anomaly system was too sensitive. We now do not report on most
anomalies unless they happen 30 times or more.
• GUI CHANGE: The “Trap Contents” menu item was renamed “Quarantine”; the latter terminology is more common.
• IMPROVEMENT: The mail queue display can be sorted by the domain of the (first) recipient.
• IMPROVEMENT (API): We now offer full API-level access to Known Networks.
• IMPROVEMENT (API): All PUT API calls now have corresponding POST calls that update
existing resources or create new ones.
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• IMPROVEMENT: The system warns if you whitelist a domain that lacks an SPF record.
• IMPROVEMENT: A user marked read-only can make absolutely *no* changes to the system,
even if he/she has administrative access. Read-only users are therefore far more useful for
helpdesk personnel than they were previously.
• BUG FIX: The rate-limiting feature sometimes would not kick in immediately when the rate
limit was exceeded. This has been fixed.
• BUG FIX: Edge-cases that could make Verification Server checks fail have been fixed.
• BUG FIX: A rare edge-case that could lose requests to remail held messages if a Storage Manager node was restarted has been fixed.
• BUG FIX: If an incident is created in a special stream, we log that stream as well as the stream
used for rules.
• BUG FIX: Some reports treated sender and recipient addresses case-sensitively resulting in
incorrect statistics. This has been fixed.
• BUG FIX (Domain-PRO only): When a realm was deleted, its children were incorrectly reparented under “base” instead of the deleted realm’s parent. This has been fixed.
• MAJOR IMPROVEMENT: Bayes tokens are now stored in Unicode. This makes CanIt far
more effective than before on non-Latin character sets. We strongly recommend that all CanIt
users upgrade just to get this feature.
• IMPROVEMENT: It is easier to add and remove scanner nodes to and from the cluster “on
the fly”. This allows you to add scanners during busy periods and remove them to save power
during quiet periods.
• NEW FEATURE: Additional system checks warn if there are too many PostgreSQL WAL files
and if there are any queue files older than 10 days in the Sendmail queue.
• NEW FEATURE (CanIt-Domain-PRO only): You can disable nightly “Anomaly Warning” notifications.
• NEW FEATURE: A “hook” mechanism has been implemented allowing custom scripts to run
when certain events occur. See the file /usr/share/canit/hooks/README for details.
• NEW FEATURE: /etc/init.d/canit-system has a new “stop-most” argument that stops almost
all CanIt services, but leaves running any services (such as PgBouncer) that are essential for
connecting to the database.
• POLICY CHANGE: By default, sender and domain whitelists are ignored for messages that fail
SPF (with a “fail” or “softfail” result.) This makes it much safer to whitelist domains such as
paypal.com or ebay.com without falling victim to phishing attacks because of the whitelist.
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• POLICY CHANGE: If a given incident is retransmitted more than 10 times from a given IP
address, we stop counting the actual number of transmission attempts. Incrementing this counter
can cause severe database contention leading to a performance slowdown.
• POLICY CHANGE: On new installations, we default to downloading and submitting RPTN
data.
• IMPROVEMENT (CanIt-Domain-PRO only): Several web pages now allow you to choose
between displaying items only in the current realm or items in the current realm and all subrealms.
• NEW API CALL: GET /api/2.0/domain recipient verification returns information about
whether or not domains correctly validate recipients and whether or not their MX records point
at the CanIt cluster.
• NEW API CALL: GET /api/2.0/realm/REALMNAME/anomalies returns the list of anomalies
for REALMNAME and all of its subrealms.
• NEW API CALL: GET /api/2.0/system check returns the list of system checks.
• PERFORMANCE IMPROVEMENT: The Storage Manager client code does not “ping” the
server as often as before, reducing Storage Manager round-trip times.
• PERFORMANCE IMPROVEMENT (CanIt-Domain-PRO only): In several places, caching has
been added to reduce database lookups on the realms table.
• DOCUMENTATION IMPROVEMENT: Note that changing a Storage Manager from
Read/Write to Read-Only or vice-versa requires restarting CanIt on that node.
• CHANGE (CanIt-Domain-PRO only): The pending notification subject by default includes the
stream name as “stream” rather than “realm:stream”. The old behaviour can be reinstated by
using “%{fullstream}” in the template.
• BUG FIX: The code for viewing the mail queue now understands Sendmail queues with separate
qf/ and df/ directories.
• BUG FIX: Under certain circumstances, a message that required streaming could be delivered
even if the streams’ Maximum Message Size parameter was smaller than the actual message
size. This has been fixed.
• BUG FIX: An error in permission calculation that could sometimes make permissions too strict
has been fixed.
• BUG FIX: If a cluster node’s inbound or outbound flag is changed, Sendmail map files are now
regenerated.
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• MAJOR NEW FEATURE: The Bayes tokenizer converts all tokens to Unicode, allowing for
tokenization of non-Latin character sets. Note that currently, the non-Latin data is not used by
the Bayes analyzer; it is used merely to feed back to RPTN and build up non-Latin tokens.
The next release of CanIt will fully support Unicode tokens and be able to tokenize mail in any
language. NOTE: This feature may double the number of .cdb files in the Bayes directories.
The double-files will be removed gradually by the next version of CanIt.
• EXPERIMENTAL NEW FEATURE: A scanner-only cluster member may be gracefully removed from the cluster (Debian Appliance only.) In this mode, the cluster member stops processing external mail and shuts down as soon as its queues have been drained.
• NEW FEATURE: The trap display indicates with an icon that a message has attachments. Hovering over the icon reveals the attachment names and MIME types.
• NEW FEATURE: Administrators can view the mail queue from within the CanIt web interface.
• NEW FEATURE: The rate-limiting feature allows you to tempfail all mail from a sender or IP
address instead of rejecting it outright.
• NEW FEATURE: A new “Header From: address of sender of CanIt notifications” lets you set
the From: header address for CanIt notifications.
• NEW FEATURE (Archiver only): The importer script lets you restrict which messages to import by date.
• NEW API CALL (Domain-PRO only): GET /realm/XXX/subtree returns the subtree of realms
rooted at XXX
• IMPROVEMENT: The “E-Mail address of CanIt System Administrator” may be set to a
comma-separated list of addresses. All addresses will receive alerts sent to the system administrator.
• IMPROVEMENT: The LDAP user-lookup lets you specify a list of attributes to use for the
stream name. The first one found is used.
• IMPROVEMENT: The LDAP user-lookup provides additional options for streaming an address
whose lookup succeeds but that lacks a stream attribute. In addition to streaming to “default”,
you can fall back on the AsIs, ChopUser or ChopDomain methods.
• PERFORMANCE FIX (Domain-PRO only): Parts of the Web interface were very slow on
installations with thousands of realms. This has been fixed.
• POLICY CHANGE: “Subject” custom rules are applied only to the decoded subject. If you
want to apply a rule to the raw subject, use a “Header” regular-expression custom rule.
• POLICY CHANGE: Our Bayes algorithm was modified slightly to thwart common Bayes poisoning attacks.
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• BUG FIX: The PDF background-report formatting could mess up if your report includes many
classifications. This has been fixed.
• BUG FIX: All short PHP tags <?= ?> have been replaced with proper <?php ?> tags because
some sites disable short tags.
• BUG FIX (Domain-PRO only): The Audit Trail feature could leak cross-realm information.
• BUG FIX: Various permission-related API bugs were fixed.
• BUG FIX: For consistency, the GET /realm/XXX/streams API call sets a “parent stream” attribute in each returned stream.
• BUG FIX: Reports would show the null sender as an empty string rather than <>. This has
been fixed.
• BUG FIX: The “Anomaly Detection” feature introduced in 8.0.12 was too sensitive. It now only
warns of anomalies that happen more than 30 times in three days.
• BUG FIX: A programming error could make the Storage Manager server enter an infinite loop
and consume as much CPU as it could grab. This has been fixed.
• BUG FIX: The failover code would not restart CanIt on the backup database server after a
failover. This has been fixed.
• NEW FEATURE: Unexpected problems (for example, errors communicating with LDAP
servers or problems with verification servers) are logged in the new Administration : Anomalies
page. If there are any anomalies, administrators (realm administrators in CanIt-Domain-PRO)
are emailed nightly.
• NEW FEATURE (Archiver only): You can reply to an archived message from within the CanIt
web interface. To prevent abuse, a given user can redeliver or reply to at most three recipients
at a time, and can reply or redeliver only once every 30 seconds.
• NEW FEATURE (Archiver only): You can view the archive as monthly “folders” making the
archiver web interface more webmail-like.
• NEW FEATURE: Filename extension rules are applied to filenames found within zip archives
as well as directly within the email. This feature is always available on CanIt appliances and is
available on other platforms if the “zipinfo” program is installed.
• EXPERIMENTAL NEW FEATURE: The archiver can import existing mail archives in mbox
or “PST” format.
• POLICY CHANGE: When a new member is added to the cluster, it is always assigned the
lowest-available host number.
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• COSMETIC IMPROVEMENT: The Reports page no longer draws pie charts with an absurdlyhuge number of pie slices. It truncates the number at 20 slices by default.
• BUG FIX: The Known Networks page would create invalid Sendmail access table entries for
IPv6 networks. This has been fixed.
• BUG FIX (Domain-PRO only): On installations with many realms, some pages would render
very slowly. This has been fixed.
• BUG FIX (Appliance only): The Sendmail aliases file was incorrectly coded as “/etc/aliases”
instead of “/etc/mail/aliases”. This has been fixed.
• BUG FIX: The code to parse Received: headers would sometimes pick out invalid IP addresses.
• BUG FIX: Invalid envelope addresses would sometimes be parsed incorrectly; this has been
fixed.
• BUG FIX: A very rare race condition in incident creation has been fixed.
• BUG FIX: In the User Lookup wizard, do not allow users to turn off “Use for Streaming” or
“Use for Authentication” if a domain is already using the user-lookup for that purpose.
• BUG FIX: Setup : HTTPS was broken by the 8.0.11 release; it is now fixed.
• BUG FIX: The trap display would sometimes produce incorrectly-sorted results when sorting
by sender address or domain. This has been fixed.
• BUG FIX: The option “Skip RBL Checks” for Network Rules was inadvertently removed despite being documented in the manual. This option has been reinstated.
• BUG FIX (CanIt-Domain-PRO only): The “rlm” URL parameter was not handled consistently
and could lead to odd behaviour in the Web interface. This has been fixed.
• NEW PERMISSIONS (CanIt-Domain-PRO only): You can now set read-only and read-write
permissions on realm expiry dates and descriptions.
• NEW FEATURE: Rather than hard-coding the number of messages per pending notification at
40, CanIt now allows you to set the limit to any number up to 1000.
• NEW FEATURE: A new preference (“Use a vertically-compact trap display”) makes CanIt try
to use less vertical space in the trap display.
• NEW FEATURE: You can specify different rate-limits for senders as opposed to IP addresses
in Known Networks. For example, you can set a limit of 100 recipients/hour for a given sender
and 500/hour for a given IP address.
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• NEW FEATURE (Archiver only): If internal mail comes from many or unknown IP addresses,
you can use a shared secret to authorize CanIt to archive mail as internal or outbound mail.
• POLICY CHANGE: For LDAP streaming methods, the default if no stream attribute is found
is to put the message in the “default” stream rather than tempfail it.
• MINOR FIX: When a sender address is auto-whitelisted, the comment added to the autowhitelist entry specifies details: (from <SENDER> via <IP>)
• INTERNAL CHANGE: The Perl CanIt::API::Client module uses JSON rather than YAML as
the serialization format. The PHP YAML parser/generator is buggy and the YAML specification
is overly-complex. Using JSON should eliminate many edge-case bugs.
• INTERNAL CHANGE: CanIt uses JSON rather than YAML for communication between cluster members. This should have no visible impact other than the elimination of a few edge-case
bugs.
• BUG FIX (Archiver only): The archiver query form would sometimes generate incorrect
queries. This has been fixed.
• BUG FIX: The C storage-manager server was not 64-bit clean. It is now completely 64-bit clean
and can store huge files on 64-bit machines.
• BUG FIX: The “Wrap Lines” feature for message preview was broken on Internet Explorer in
CanIt 8.0.10. It is now fixed.
• EXPERIMENTAL FEATURE: Bayes data can be retrieved from Storage Manager rather than
local CDB files. This feature is not yet ready for general use.
• MINOR FEATURE: When previewing a message, you can request that the browser wrap long
text lines.
• MINOR FEATURE (CanIt-Domain-PRO): API calls that retrieve realm information return the
full path from the realm to “base”.
• UPDATE: Update to ClamAV 0.97.3.
• BUG FIX: CanIt Storage Manager was not 64-bit clean and would fail to store files over 2GB
on 64-bit systems. This has been fixed.
• BUG FIX: The web interface correctly validates each Verification Server if you enter more than
one for a given domain.
• BUG FIX: The Audit Trail feature now works for Global Settings.
• BUG FIX (Archiver): A query with an OR clause would not respect date restrictions properly.
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• BUG FIX (Archiver): The archiver would fail to parse a References: header that looked like
this: <msgid1><msgid2><msgid3>...
• BUG FIX (Log Searcher): The “what” field is a now pulldown rather than a free-form text field.
• BUG FIX (Archiver): The archive indexer could sometimes overflow an internal PostgreSQL
limit, causing indexing failures and enormous PostgreSQL logs. This has been fixed.
• NEW FEATURE: Many reports now keep statistics on message sizes as well as message counts.
(For example, you can pull a report showing daily message byte traffic.) Note that the byte
count data is not available for historical data—it is only available for messages received after
upgrading to 8.0.9.
• NEW FEATURE: A general-purpose key/value storage system available via the API has been
implemented. This can be used for integration with other applications, for storing provisioning
data, etc.
• POLICY CHANGE: Messages held for filename extension, MIME type, etc. rules are still
spam-scanned and assigned a score. This permits auto-rejection of messages that would otherwise be held unnecessarily. It also permits messages with Hold-policy attachments to be
tokenized for Bayes training.
• POLICY CHANGE: If a user chooses not to add voting links to whitelisted messages, this setting is honored for all kinds of whitelists. Previously, it was honored only for sender whitelists.
• POLICY CHANGE: “Hold” settings have been renamed “Hold/Tag” to emphasize that they
now tag the subject in a tag-only stream.
• POLICY CHANGE (CanIt-Domain-PRO only): If a realm is deleted, child realms become
children of the deleted realm’s parent rather than unconditionally becoming children of “base”.
• IMPROVEMENT: Many new templates have been added. These permit (for example) translation of many CanIt-generated email messages.
• BUG FIX: Upper-case host names would cause cluster management to have problems. This has
been fixed.
• BUG FIX: Some API calls would return an empty YAML document when they really should
have returned a zero-element array. This has been fixed.
• BUG FIX: The templating method “T->menu items()” did not return correct values for submenus; this has been fixed.
• BUG FIX: The new “Rewrite” user-lookup method didn’t appear as a possible streaming method
in Domain Mappings. This has been fixed.
• BUG FIX: Some API calls mis-handled mixed-case host names; this has been fixed.
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• BUG FIX: If the EHLO command fails when running a Verification Server check, we send a
RSET before the HELO as per the SMTP standard.
• NEW FEATURE (Archiver only): CanIt can take a search expression and generate a zip file
containing all archived messages that match. You can also configure CanIt to zip up archived
mail just before it expires from the archive.
• NEW FEATURE: The new “Rewrite” user-lookup permits you to map email addresses to
streams using a simple rewriting expression.
• NEW FEATURE: Old Bayes databases are removed by the nightly cron job. An “old” database
is defined as one that has not been trained in a given timespan (by default, 365 days.)
• NEW FEATURE: A nightly system check warns if any local filesystem has less than 10% space
remaining.
• NEW FEATURE: The rate of sending Pending Notifications can be throttled. This can help
prevent excessive CPU usage if many notifications need to be sent.
• IMPROVEMENT (Appliance only): If the Log Forwarder has trouble forwarding logs to a
remote server, it logs more informative error messages to make it easier to find the problem.
• IMPROVEMENT (Domain-PRO only): Realm administrators can view both a flat list of realms
and a tree view. Previously, they could only see the tree view.
• UPGRADE: Update ClamAV from 0.97.1 to 0.97.2
• BUG FIX: The RSS Feed feature could inadvertently show incidents in other streams. This has
been fixed.
• BUG FIX: The “Clean Looks” theme did not include links to the manuals. This has been fixed.
• BUG FIX: The API code could occasionally mis-handle mixed-case domain names. This has
been fixed.
• BUG FIX: Warnings about undefined variables in the DKIM module were suppressed.
• NEW FEATURE (Archiver): The archiver permits construction of complex boolean search
queries. You can also save queries for later re-use.
Because of the new method of query construction, the API call for searching the archive has
changed. Please read the API Guide for details.
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• NEW FEATURE: You can specify whether a Verification Server entry should always queue
mail if the verification server is down, or queue only for addresses seen in the last 60 days.
• PERFORMANCE IMPROVEMENT: Pending Notifications are sent with Sendmail’s SuperSafe
flag set to “off”. We feel this is an acceptable tradeoff between safety and performance.
• COSMETIC FIX: The layout of the “Known Networks” page has been changed so you can
easily compare settings across networks rather than having to expand individual networks to see
their settings.
• COSMETIC FIX: The “Viewing Stream xxx” display has been streamlined and made more
unobtrusive.
• POLICY CHANGE (CanIt-Domain-PRO only): Realm administrators are allowed to set the
“Full name for sender of CanIt notifications” template.
• BUG FIX: For hosts marked “Inbound” only, we remove the normal mailertable entries that
CanIt would create based on the Domain Routing table.
• BUG FIX: The “Sharded Database” add-on component would ignore the specified
db connect timeout. This has been fixed.
• BUG FIX: canit-failover-verify-setup.pl would sometimes incorrectly complain about a misconfiguration when in fact there was no misconfiguration. This has been fixed.
• BUG FIX: The API would sometimes fail if PHP’s “magic quotes gpc” setting was enabled.
• BUG FIX: The Domain Routing page no longer accepts a domain of “*” (which would cause
routing problems.)
• BUG FIX: The LDAP User Lookup does not insist on a non-blank Base DN (it can be empty
according to RFC 2253.)
• BUG FIX: If the PhishingAddress plugin action was set to “Reject” but a message scored over
the hold threshold, it would be held instead of rejected. This has been fixed.
• BUG FIX: The log-searching code could return incorrect results if you have more than one log
host. This has been fixed, but log-searching with more than one log host is slower. We will
address the speed regression in a future release.
• BUG FIX: The failover code now copies pg xlog directories when making a base backup. This
is required for older versions of PostgreSQL.
• NEW FEATURE (Archiver): We now include several reports such as messages and bytes
archived per day and number of email addresses with archived mail.
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• NEW FEATURE (Archiver): You can ask CanIt to redeliver an archived message to the email
address(es) of your choice.
• NEW FEATURE (Archiver): You can now do a substring search on envelope recipients in
addition to exact matching.
• NEW FEATURE (Archiver): CanIt can now archive internal and outbound email using the
SMTP Journalling feature of Microsoft Exchange 2007 and 2010. (2003 is not supported yet.)
• NEW FEATURE (Domain-PRO only): The pseudo-user *localroot* may be used to grant permissions to realm administrators without also granting them automatically to administrators of
sub-realms.
• IMPROVEMENT: Each CanIt node periodically measures the latency to all Storage Manager
nodes and uses them in order of ascending latency. Thus, reads are preferably done on “close”
machines, improving performance and potentially decreasing bandwidth across WAN links.
(See the Administration Guide for more information and for information on overriding the order
of Storage Manager accesses.)
• IMPROVEMENT (Archiver): You can choose whether or not you wish to archived tagged mail
for tag-only streams. The default is to archive tagged mail.
• IMPROVEMENT (Archiver, Domain-PRO only): You can specify in which realms internal
machines may archive internal email.
If you have used the Authorized Hosts feature of Archiver with Domain-PRO, you need to
re-enter the hosts and specify which realm(s) are applicable to each host.
• IMPROVEMENT: The log-forwarding feature now imposes timeouts on logs transported via
TCP so as not to stall log-forwarding if a log host is down.
• COSMETIC IMPROVEMENT: Large numbers in reports are displayed in a more humanreadable format. In the HTML table, the human-readable format is visible if you hover over
the raw number.
• BUG FIX: All links in CanIt-generated messages have the rel=“nofollow” attribute. This is to
reduce the chances of search engines crawling the links and inappropriately causing CanIt to
take actions.
• BUG FIX: CanIt rejects unauthenticated actions if the user-agent is one of a number of known
search-engine crawlers. This prevents (for example) messages from being inappropriately accepted or rejected if a notification message accidentally winds up getting indexed by Google,
Yahoo!, etc.
• BUG FIX (Appliance Only): canit-system bails out immediately if it detects an upgrade in
progress. This should avoid complaints from cron during CanIt Appliance upgrades. [Unfortunately, the fix will only apply when upgrading from 8.0.6 to the next version.]
• BUG FIX: Some obscure edge-cases in the Web interface code that could cause redirect loops
were fixed.
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• BUG FIX: The “dormant stream” report no longer reports special streams or forced-to streams.
• POLICY CHANGE: The Bayes tokenizer uses a proper HTML parser to extract tokens from
text/html parts. This should give better results than the older naive parser.
• MAJOR NEW FEATURE: CanIt-Archiver keeps an audit trail of searches and message accesses. Administrators and end-users can see the audit trail. (End-users can only see audit trails
relating to their own archive.)
• MAJOR NEW FEATURE: CanIt-Archiver has a hook for archiving internal email that normally
would not be seen by CanIt.
• NEW FEATURE (CanIt-Domain-PRO only): Realm administrators can be granted access to
realm user fields on a per-user, per-field basis.
• NEW FEATURE: For User-Lookups that cache results in the database, the default cache expiry
has been changed from 24 hours to 120 hours. A new parameter (Cache Refresh Time) causes
CanIt to attempt to refresh cache entries older that 12 hours, but continue to use entries up to
the cache expiry time.
• MAJOR IMPROVEMENT: CanIt-Archiver compresses archived messages using “bzip2” compression.
• MAJOR IMPROVEMENT: CanIt-Archiver stores only one copy of duplicate messages received
on a given day for a given realm.
• PERFORMANCE IMPROVEMENT: Bayes data is synchronized to all scanners in parallel from
the ticker host rather than sequentially.
• UPDATE: Our appliance ISO images are now based on Debian 6.0 (“squeeze”) instead of 5.0
(“lenny”)
• BUG FIX: Envelope and header senders are now compared case-insensitively to determine
whether or not to display a warning that they differ.
• BUG FIX: Messages with encoded subjects would not show up in archive searches that should
hit words in their subjects. This has been fixed.
• BUG FIX: A rare edge-case could break statistics collection if you use Storage Manager and
accept mail over IPv6. This has been fixed.
• BUG FIX: Setting a storage manager node “read-only” works as expected; before, the Storage
Manager wizard did not distinguish properly between read-only and read/write nodes.
• BUG FIX: The RunBayesJournal task has been modified to ensure that it can keep up with the
rate of incoming training requests. If it is unable to keep up, then it trains a sample of requests
rather than all of them.
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• EXPERIMENTAL NEW FEATURE: We have an email archiving component for CanIt. This
extra-cost add-on component is available only on our Debian-based appliances and is considered
to be beta software at this point. Contact your sales representative if you are interested in testing
it.
• POLICY CHANGE: CanIt now shows the header From: address rather than the envelope sender
address in the Trap Contents display. This address is more likely to be useful for whitelisting or
blacklisting than the envelope sender.
• POLICY CHANGE: If the “auto-populate notification address” setting is set to “Yes”, we do
*not* set the notification address for a forced-to stream. Setting the address could result in
leaking of sensitive information.
• NEW FEATURE: The “View this Stream” text box uses auto-completion to suggest stream
names.
• BUG FIX (CanIt-Domain-PRO only): You can now set a realm’s parent realm via the API.
• BUG FIX: You can now allow blacklist/whitelist sender options for “Clickable HTML” notifications.
• BUG FIX: The notification template has a new %{fullurl} replacement tag that is substituted
with the full URL of an incident.
• BUG FIX (CanIt-Domain-PRO only): A very rare edge-case could create a user that could never
be deleted from the Web interface. This has been fixed [and all such users are deletable now.]
• BUG FIX: Timeouts for Storage Manager are now configurable and are correctly implemented
for both single-node and multiple-node installations.
• BUG FIX: The log-searching API controller would sometimes fail; this has been fixed.
• BUG FIX: Suppress use of uninitialized variable errors in Bayes tokenizer.
• NEW FEATURE (CanIt-Domain-PRO appliance only): The log-indexer can forward log lines
(using the SYSLOG protocol) to remote hosts on a per-realm basis.
• IMPROVEMENT: Reduce the disk I/O consumed by the log-indexing daemon.
• POLICY CHANGE: Access to “Search Logs” is now controlled by a separate permission rather
than the “View Trap” permissions.
• POLICY CHANGE: We have clarified the licensing terms of our data feeds such as RPTN and
our RBLs. Please see the LICENSE.TXT file for details.
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• POLICY CHANGE: On CanIt appliances, we now auto-create a mail alias for “root” that goes
to the CanIt Administrator email address.
• UPDATE: Upgrade to ClamAV 0.97.
• BUG FIX: Package a missing cron task in canit-log-correlator.
• BUG FIX: When searching logs, correctly handle the case when the index is updated during a
search.
• BUG FIX: Fix a number of deprecation warnings with PHP 5.3.
• BUG FIX: Fix typo in theme file that caused browser to request a nonexistent CSS file.
• NEW FEATURE: In addition to rate-limiting outbound mail by sender, you can also rate-limit
it by originating IP address.
• NEW FEATURE (Appliance only): Implemented new API calls to perform log searches. Note:
The API client libraries were updated to permit query parameters on GET requests; to use the
new API calls, you will need to use the latest API client libraries.
• POLICY CHANGE: We have a new “Mixed” real-time DNS-based list. This list includes hosts
that send a large amount of both spam and non-spam. They should be penalized somewhat, but
not as much as hosts in “SpamSource”.
• GUI IMPROVEMENT: All pages display the “Pager”, “Filter” and “Enter specific object” elements in that consistent order.
• BUG FIX: The audit-trail for Preferences did not work; it works correctly now.
• BUG FIX: MIMEDefang failed to install on (really old versions of) FreeBSD. This has been
fixed.
• BUG FIX: Voting links were sometimes not removed even if they should have been. This has
been fixed.
• BUG FIX: The log-indexer would sometimes produce incorrect timestamps when indexing log
files. This has been fixed.
• BUG FIX: A third-party PHP module was not compatible with PHP4. We have backported it.
• BUG FIX: The new Web code broke the RSS Feed feature; this has been fixed.
• BUG FIX: A minor display problem when clicking on the message subject in a Pending Notification message has been fixed.
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• BUG FIX: A very rare edge case in the PHP code that could produce illegal SQL has been fixed.
• BUG FIX: In very rare cases, a dead storage manager node could cause a scanning process to
terminate unexpectedly. This has been fixed.
• BUG FIX: On appliances, clamd could be disabled unintentionally during an upgrade. This has
been fixed.
• BUG FIX: The Verification Server feature could sometimes misinterpret an ESMTP “SIZE”
keyword from the back-end server. This has been fixed.
• BUG FIX: Remove deprecated call-time pass-by-reference instances in the PHP code.
• DOC FIX: In the Administration Guide, document the fact that the SNMP agent requires a
helper cron job to run once a minute.
• MAJOR NEW FEATURE: CanIt keeps an audit trail of all changes to settings, rules, etc. You
can review the audit trail from most pages by clicking “Show Changes”.
• MAJOR NEW FEATURE: CanIt can perform full-text indexing and searching of all mail logs.
Note that this feature is available only on our Debian appliances (“Lenny” release) and is not
installed by default. See the Administration Guide for installation details.
• NEW FEATURE: All of the online documentation can now be searched live from the CanIt
interface.
• MAJOR CHANGE: The PHP Web interface has been completely rewritten, making theming
much easier.
IF YOU HAVE THEMED CANIT, YOU WILL NEED TO REWORK YOUR CUSTOMIZATIONS
• POLICY CHANGE: We no longer provide binary RPMs for SuSE Linux Enterprise Server 9.
• POLICY CHANGE: Default database connection timeout has been increased from 10 seconds
to 20 seconds. 10 was causing problems on some systems.
• POLICY CHANGE: In a Verification Server entry, if you choose “Queue” rather than “Tempfail” when the back-end server is down, CanIt only permits recipients who have been seen within
the last 60 days. It tempfails any others. This makes it much safer to use “Queue” with much
less risk of backscatter.
• UPDATE: Update ClamAV from 0.96.4 to 0.96.5.
• NEW FEATURE: The Pending Notification page has a button to send a notification immediately.
276
• NEW FEATURE: We now have IPv6 geolocation data (though it is less granular than the IPv4
data, listing only the country.)
• NEW FEATURE: When the failover code fails over, it executes all scripts in
/usr/share/canit/failover/notify.d/ This lets you write scripts to send administrators notice that
the database has failed over.
• NEW API CALLS:
/realm/@@/streams/with pending: List streams with new pending incidents.
/realm/@@/stream/@@/pending flag: Get/set the Pending Notification flag.
/realm/somerealm/realm mappings: Get all realm mappings for a given realm.
• API IMPROVEMENT: The API returns more information about incidents than before, including sender, recipient, host, etc.
• IMPROVEMENT: (CanIt-Domain-PRO only): A configuration file setting lets you use AJAXenabled auto-completing text fields wherever a realm entry box appears. The AJAX code has
been optimized since the previous release and should be much faster, especially for the site
administrator.
• IMPROVEMENT: Verification Server SMTP callbacks understand the ESMTP “SIZE” keyword.
• IMPROVEMENT: You can control caching of invalid recipients and invalid recipients using
memcached independently. (For example, you can cache valid recipients, but not invalid ones.)
• IMPROVEMENT: The Permissions page forces you to enter a stream class if there isn’t one
instead of silently ignoring input.
• IMPROVEMENT: The POP3 authentication method would fail against Exchange 2007 and
newer because of a Microsoft bug. We have code in CanIt to work around Microsoft’s bug.
• COSMETIC IMPROVEMENT: The charts displayed in Reports have been improved: Redundant trailing zeros are deleted and all load charts are lined up.
• COSMETIC IMPROVEMENT: The User Lookup test page has been made clearer. Tests that
can’t work for a particular user lookup method are suppressed.
• BUG FIX: If the system has been configured to force user-names to lower-case, then all components of the system enforce that setting on data entry.
• BUG FIX: When CanIt stripped out existing training links from messages, it would sometimes
be a bit greedy and strip out too much of the message. This has been fixed.
• BUG FIX: SNMP monitoring code has been rewritten and cleaned up. Permissions problems
with monitoring PostgreSQL have been fixed.
The SNMP code has changed to require only a single SNMP agent process. If you have configured SNMP, you will need to reconfigure it to use the new SNMP agent.
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• BUG FIX: sendmail-account-info.pl could occasionally fail. (This affects very few people...)
• BUG FIX: Update the Python API client library to work with Python 2.6 and later.
• BUG FIX: In CanIt-Domain-PRO, the Domain Setup Wizard would sometimes create a Verification Server entry in the base realm instead of the appropriate realm. This has been fixed.
• NEW FEATURE: CanIt now has built-in support for DKIM (DomainKeys Identified Mail). See
http://dkim.org for a description of DKIM.
• NEW FEATURE: We have experimental support for Vouch By Reference (RFC 5518). We may
change the way it is implemented in a future release of CanIt, but will provide an automatic
upgrade path.
• IMPROVEMENT: If you are using outbound rate limiting *and* use SMTP AUTH on the CanIt
server, we limit outbound mail based on the authentication name as well as the purported envelope sender. This is to avoid spammers bypassing rate limiting by changing the sender address.
• NEW API CALLS: GET /realm/xx/stream/yy/addresses seen and GET /realm/xx/domains seen
return statistics about observed email addresses per stream/realm.
• IMPROVEMENT: Graphical reports now show statistics for “bad” things (eg spam and viruses)
using a reddish palette and “good” things using a greenish palette.
• IMPROVEMENT: The failover scripts include additional checks to prevent certain misconfigurations.
• IMPROVEMENT: You can specify a database connection timeout. This improves response time
if you have configured a databaseless-filter mode and the database is down. The default timeout
is 10 seconds.
• UPGRADE: Updated ClamAV to version 0.96.4.
• PLATFORM SUPPORT: We have dropped support for RPMs for Red Hat Enterprise Linux 3.
We have dropped binary package support for Debian Sarge (3.1).
• POLICY CHANGE: The CanIt Appliance setup screen will not let you name your CanIt host
“something.local” or “something.localdomain”.
• BUG FIX: The username “defang” was hard-coded in a few places. Now everything respects
the setting in canit.conf.
• BUG FIX: Verification Servers were documented as taking a “/port” suffix. Now that actually
works!
• BUG FIX: In the API server, using ’@@’ for realm and/or stream now works as documented.
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• BUG FIX: A long-standing bug that could cause Pending Notifications to fail if there are pending messages with invalidly-encoded subjects has been fixed.
• BUG FIX: The old message-hashing algorithm could sometimes consider two different messages to be the same incident. This has been fixed, but there will be a transition period of
several days for your CanIt installation to move completely to the new algorithm. (We must
retain the old algorithm until all incidents hashed with it have expired.)
• MISCELLANEOUS: Many minor bug fixes and code cleanups.
• POLICY CHANGE: Add default rules for the Roaring Penguin reputation lists.
*** NOTE *** If you are already using our lists, please check the RBL rules in the default
stream (base realm in Domain-PRO) carefully after upgrading!
• NEW FEATURE: You can configure CanIt to create an incident for all messages, even nonspam ones. The feature is disabled by default and we do not recommend enabling it on busy
sites.
• NEW FEATURE / POLICY CHANGE: The default notification format has been changed to
“HTML with Links” instead of “Clickable Webform”. The “Clickable Webform” form fails in
many email clients.
• NEW FEATURE: Add a button to the Preferences : Notification page that allows a user to
request an immediate notification.
• UPDATE: Prepare CanIt to work properly with forthcoming PostgreSQL 9.0.0.
• MINOR IMPROVEMENT: Add a “tag” field in Master RBL List. This tag (if present) is used
in log messages rather than the long RBL name.
• IMPROVEMENT: Add more convenient do get, do put, do delete and do post methods to Perl
API client library.
• IMPROVEMENT (CanIt-Domain-PRO only): Instead of a pull-down list of realms, you
can use an AJAXy auto-completion text field in the “Switch Realm” box. See $Config[’RealmSelectWidget’] in the config-domain-pro.php file.
• BUG FIX: The API server includes the “parent” field of each realm in the “GET /realms” result.
• BUG FIX: Previously, the API server did not convert a user name of ’@@’ to the logged-in
username. Now it works as advertised.
• BUG FIX: The Known Networks page would sometimes display a spurious error message ”You
cannot use Force To Stream on a network containing 127.0.0.1 or ::1” This has been fixed.
279
• BUG FIX: Uploading an SSL certificate under Setup : HTTPS would put the certificate on all
cluster members. Now it only puts it on the particular web server that your browser communicates with.
• BUG FIX: When disposing of locally-held messages, correctly report the sending relay to the
Roaring Penguin Reputation Collection system.
• BUG FIX: Properly implement the retry-delay for dead Storage Manager nodes.
• BUG FIX: Use the –compress flag on all “rsync” commands.
• BUG FIX: Do not check RPTN data for freshness on cluster members that are not marked as
“Sync Bayes?” nodes.
• NEW FEATURE: CanIt can stream inbound messages by directly injecting files into the Sendmail client queue. This can significantly improve performance and reduce disk I/O when streaming messages.
• IMPROVEMENT (CanIt-Domain-PRO only): Realm administrators now have access to the
Greylisting Report.
• POLICY CHANGE: SORBS has been removed from the suggested set of useful RBLs.
• BUG FIX: The “Known Networks” cache size has been increased to avoid “ping-ponging” the
cache in certain situations.
• BUG FIX: The sample PHP API client code now implements DELETE.
• BUG FIX: The CanIt-Connectwise integration module no longer uses the DateTime module.
• BUG FIX: Subject lines in the Pending Notification messages would sometimes be converted
to UTF-8 incorrectly. This has been fixed.
• BUG FIX (CanIt-PRO only): Brand new installations would fail with a PHP error. This has
been fixed.
• BUG FIX: On CanIt-PRO only, if the login/password were the default “admin/canit”, the system
would fail with a fatal PHP error. This has been fixed.
280
• UPDATE: Update MIMEDefang to 2.70
• NEW FEATURE: Scanners can be marked as “Inbound” and/or “Outbound”. You can also mark
a scanner as not needing Bayes data if it’s only used for outbound scanning.
• IMPROVEMENT: You can specify whether an RBL applies to IPv4 addresses, IPv6 addresses
or both.
• IMPROVEMENT: The Bayes calculation handles edge-cases better rather than biasing them
towards “spam”.
• IMPROVEMENT: The stream (and possibly realm) are included in the URLs generated by
Pending Notifications.
• CHANGE: The “User”, “PID File” and “Root Directory” settings for Storage Manager are now
specified in canit.conf rather than being stored in the database and updated via the Web interface.
This allows you to use different values on different machines, and also makes the canit-system
startup script more robust in the face of a missing database.
• CHANGE: “Sender-Whitelisted” messages are reported to RPTN (but not trained locally.)
• CHANGE: We no longer track the “Expired from Trap” statistic. Instead, when an incident is
created, it increments a new “Quarantined” statistic.
• BUG FIX: IPv6 addresses were not always correctly parsed out of Received: headers; this has
been fixed.
• BUG FIX: Avoid useless DNS lookups in CanIt::Socket.
• BUG FIX: Make notifications stream settings accessible via API.
• BUG FIX: Auto-whitelisting could inadvertently create mixed-case sender rules. This has been
fixed.
• BUG FIX (CanIt-Domain-PRO only): A realm’s “default” stream always inherited from
base:default even if the admin had explicitly turned off inheritance. This has been fixed.
• BUG FIX: The LDAP lookup Perl code broke with very new versions of Net::LDAP. This has
been fixed.
• BUG FIX: The test for Blacklisted Recipients was case-sensitive; this has been fixed.
• BUG FIX: If you had a wildcard Verification Server, it would sometimes be used even if there
was a more-specific entry. This has been fixed.
• BUG FIX: Country Code rules can now be exported to CSV files and imported from CSV files.
• BUG FIX: The Web interface formerly took quadratic time to obtain the tree of realms; it now
takes linear time.
281
• BUG FIX: Provide API-level access for setting a stream’s parent.
• BUG FIX: Improve CanIt API server handling of JSON vs YAML.
• IMPROVEMENT: HTTPS (with self-signed certificates) is enabled on appliances by default.
• DOCUMENTATION FIX: Fix typo in Administration Guide Memcached configuration instructions.
• BUG FIX: Allow a wildcard SPF rule (broken in 7.0.0).
• BUG FIX: Add workaround for ancient Perl LWP library shipped with Red Hat Enterprise
Linux 4.
• BUG FIX: Periodic Reports were broken on CanIt-PRO. They have been fixed. Note: If you are
upgrading from pre-7.0.0, you may still have to edit all of your charts and save them to update
the stored report configuration.
• BUG FIX: Avoid warning caused by ancient version of PostgreSQL shipped with Red Hat
Enterprise Linux 4.
• BUG FIX: Only allow selection of LDAP (Active Directory) when first creating a User Lookup.
Thereafter, it becomes (and stays) LDAP (Generic).
• BUG FIX: Suppress pointless warning when entering a Verification Server of “ignore”.
• BUG FIX: Prevent startup code from always registering a new cluster member as a standalone
machine.
• BUG FIX: Don’t attempt DNS lookups on hostnames that are already IPv4 or IPv6 addresses.
• BUG FIX: 9-digit old-style incident IDs would cause the work journal task to fail. This has
been fixed.
• BUG FIX (CanIt-Domain-PRO only): Allow Base URL of CanIt Installation to be set on a
per-realm basis.
• UPDATE: Update to ClamAV version 0.96.
• BUG FIX: Remove the long-obsolete “Sendmail” domain-mapping option.
• BUG FIX: Subject lines with NUL characters could produce badly-rendered Pending Notification reports. This has been fixed.
• BUG FIX: Fix compilation error in Storage Manager on Gentoo.
282
• BUG FIX: Avoid spurious warning in database upgrade script.
• BUG FIX: Include correct text in incident report when sender is whitelisted due to SMTP
AUTH.
• BUG FIX: Fix the optional “Next Msg” and “Prev Msg” links in the incident details page; these
were broken by the 7.0.0 release.
• BUG FIX: In 7.0.0, a user-lookup method whose name matched the method name would fail.
• BUG FIX (CanIt-Domain-PRO only): The 7.0.0 upgrade accidentally reduced the permissions
of realm administrators. This has been fixed.
• BUG FIX: The Known Networks page produced invalid HTML; this has been fixed.
• BUG FIX: The database upgrade script could fail on certain databases that were upgraded from
old versions of PostgreSQL. This has been fixed.
• MAJOR NEW FEATURE: CanIt can automatically block senders who send too many messages
per hour. This rate-limiting is controlled by a Known Networks flag and can be used to detect
and block internally-compromised email accounts.
• MAJOR NEW FEATURE (CanIt-Domain-PRO only) Realms can now be hierarchical. This
allows many levels of administrative control; a customer in charge of a realm can be allowed to
manage sub-realms.
• MAJOR NEW FEATURE: CanIt installations collect data about IP address reputation and send
the data back to Roaring Penguin Software. This will be used to build a set of DNS-based
blocklists usable by CanIt customers. NOTE: You should open UDP port 6568 outbound so the
CanIt machines can report the IP reputation data.
• MAJOR CHANGE: The API server has been rewritten in PHP. As a result, it is much easier
to deploy and does not need FastCGI or Catalyst. Also, if you choose, you can make the API
available to realm administrators or even end-users. (Normal permission checks apply.)
The API version number has changed from 1.0 to 2.0. You should rework any scripts that use
the API and make sure they still work correctly.
• MAJOR CHANGE: Incident IDs are no longer integers, but string identifiers. This is to support a future add-on component that allows CanIt incident data to be spread across multiple
PostgreSQL servers.
• MAJOR NEW FEATURE: Roaring Penguin Software Inc. provides four new DNSBLs to CanIt
customers; see the Administration Guide for details.
283
• NEW FEATURE: Master RBL’s can be marked “Block” or “Allow”, which controls the RBL
rules that can be created.
• NEW FEATURE: You can extend the enforced greylisting “quiet time” for hosts listed on a
DNSBL.
• NEW FEATURE: (CanIt-Domain-PRO only) You can store up to four user-defined pieces of
information per realm.
• ENHANCEMENT: DNSBLs now let you specify an A record to match or a bitmask to mask
against. This lets CanIt handle combined DNSBLs that return multiple pieces of information
encoded in the A record.
• UPGRADE: Upgraded SpamAssassin from 3.2.5 to 3.3.0.
• IMPROVEMENT: You can set a timeout on Verification Server lookups and User Lookups.
• IMPROVEMENT: “Subject” custom rules apply to both raw and decoded subject lines.
• IMPROVEMENT: CanIt Storage Manager packs old data into CDB databases; this reduces the
number of files in the Storage Manager Tree making it easier to back up and consuming fewer
inodes.
• IMPROVEMENT: The Sanity Checker module checks for many more problems and misconfigurations.
• IMPROVEMENT: The Dictionary Attack Detector uses a Known Networks flag to avoid banning friendly hosts. This replaces the older text entry box with a list of hosts.
• IMPROVEMENT: The “Clickable Webform” Pending Notification has been improved so large
pending lists don’t generate over-long URLs. Also, all subject lines are decoded and presented
in UTF-8.
• IMPROVEMENT: The failover code refuses to fail over if the standby database is active for
some reason.
• IMPROVEMENT: WAL-file copying in the failover code has been made more robust.
• IMPROVEMENT: System Load graphs are now in a zoomable vector format on browses that
support the HTML Canvas tag (this means any modern browser except Internet Explorer.)
• IMPROVEMENT: The API always returns a stream’s parent when returning stream data.
• IMPROVEMENT: DNSBL descriptions are shown in the Spam Analysis Report.
• IMPROVEMENT: We don’t use DB File unless we actually encounter a Berkeley DB file. This
can reduce memory usage.
• IMPROVEMENT: French and Portuguese translations have been overhauled.
• SECURITY ENHANCEMENT: The “goto” redirection parameter is sanitized to avoid crosssite scripting attacks.
284
• IMPROVEMENT: (Appliance only) The curses-based “setup” utility lets you reset CanIt user
passwords.
• IMPROVEMENT: (CanIt-Domain-PRO only) Many formerly-global settings like the CanIt administrator email address are settable on a per-realm basis.
• PERFORMANCE IMPROVEMENT: You can use memcached to cache Verification Server results.
• MINOR NEW FEATURE: You can purge all rules and settings from a stream.
• MINOR NEW FEATURE: You can remove permission for end-users to disable stream inheritance.
• MINOR IMPROVEMENT: Text in the “Strip Attachments” notification is now templatable.
• MINOR IMPROVEMENT: You can set the default action for the “Clickable Webform” notification, and also add “Blacklist/Whitelist Sender” options to the notification.
• MINOR IMPROVEMENT: You can tell the LDAP lookup not to validate the server certificate
(if, for example, it uses a self-signed certificate.)
• MINOR IMPROVEMENT: System Check test names are hyper-linked to descriptions in the
Administration Guide.
• PERFORMANCE IMPROVEMENT: The Storage Manager server uses “sendfile” to send data
if possible. Otherwise, it tries “mmap” and only as a last resort falls back to “read/write”.
• CLEANUP: The database schema has been cleaned up to improve performance and maintainability.
• GUI CLEANUP: The Pending Trap displays incident dates in a more readable way.
• GUI CLEANUP: The Known Networks interface has been reworked to avoid very wide pages
that require side-scrolling.
• POLICY CHANGE: The “Handling for Windows Executables” setting has been removed. Instead, use Filename Extension rules. On upgrade, appropriate Filename Extension rules are
created to keep the same behaviour as the pre-upgrade version.
• POLICY CHANGE: The “Secondary MX Machines” setting has been removed. Instead, use
Known Networks flags. On upgrade, appropriate Known Networks entries are created.
• POLICY CHANGE: We no longer tokenize Microsoft Word documents. They were leading to
too many false positives. This change may be revisited in a future release.
• POLICY CHANGE: The “Database Cron Runner” flag in Cluster Management has been ignored since release 6.1.0. The flag has therefore been removed.
• BUG FIX: We don’t count addresses in addresses seen unless a domain is known to validate
recipients.
285
• BUG FIX (Appliance only): The “Set Timezone” menu option now works properly and actually
sets the time zone.
• BUG FIX: Bayes training is more robust in the face of corrupt CDB files.
• BUG FIX: Known Networks would refuse to allow a “Force-to-Stream” value for SMTPAUTH. This has been fixed.
• BUG FIX: The “Top N” reports in long-term statistics used to issue PHP errors on PHP 5.3; this
has been fixed.
• BUG FIX: CanIt would incorrectly force local parts of email addresses to lower-case when doing verification server lookups. This can break things like SRS, so we leave the local part alone
now. (For the purposes of rules, however, the local part is still compared case-insensitively.)
• BUG FIX (Domain-PRO only): Realm Administrators are now given full access to traps within
their realms.
• BUG FIX: Daily reports were broken on PHP 5.3.
• BUG FIX: Remove all PHP calls to the deprecated “ereg*” functions in favour of “preg*”
• BUG FIX: (CanIt-Domain-PRO appliance only) Deleting a realm also deletes domain routes
associated with the realm.
• BUG FIX: SPF “permerror” and “temperror” returns codes are handled properly.
• BUG FIX: Oversize text/plain parts are no longer scanned with SpamAssassin.
• BUG FIX: The system is much more robust in the face of corrupt Bayes CDB files.
• BUG FIX: canit-failover-verify-setup.pl would report a spurious test failure.
• BUG FIX: CSS stylesheets have been fixed up to have more consistent font selection.
• BUG FIX: Make startup code regenerate mailertable and access databases on appliances.
• BUG FIX: Make startup code coexist more peacefully with PgBouncer.
• BUG FIX: Fix errors in IPv6 validation in Rules : Networks.
• BUG FIX: Force scanners to notice changes to Known Networks immediately.
• BUG FIX: Make “PUT /domain routes/activate” API command actually work.
• MINOR BUG FIX: Suppress warnings that cron job has not run on new installations; we only
trigger the test after system has been installed for at least a day.
• MINOR BUG FIX: Fix possible print formatting error in Custom Rule test.
286
• MINOR BUG FIX: Suppress “Use of uninitialized variable” warning in Bayes code.
• MINOR BUG FIX: Make Bayes sync work on symbolically-linked source directories.
• BUG FIX: Total token counts for local streams were being reset to zero. This has been fixed.
Note that no Bayes training was lost; only the token counts in the PostgreSQL database were
affected. As streams undergo Bayes training, the token counts will be corrected automatically.
• BUG FIX: On certain systems, the database upgrade code would fail. This has been fixed.
• BUG FIX: In some cases, depending on how it was sorted, the trap display would produce an
SQL error. This has been fixed.
• BUG FIX: Storage manager refused to compile on NetBSD; this has been fixed.
• NEW REPORT: A “Dormant Streams” report lists all streams that have not received mail in the
last 60 days.
• NEW FEATURE: “Host” rules have been replaced by “Network” rules, which can apply to
CIDR blocks as well as individual hosts.
• NEW FEATURE: We have *experimental* support for IPv6. Anywhere an IPv4 address can be
used, so can an IPv6. And anywhere an IPv4 CIDR can be used, so can an IPv6 CIDR. Please
note that there may be many untested edge cases, hence the designation “experimental”.
• NEW FEATURE (CanIt-Domain-PRO only): Realms can have an expiry date; when it nears,
realm administrators get a warning. This lets hosting providers keep track of when customer
services are to expire.
• MINOR NEW FEATURE: The trap display can be sorted by the domain of the sender.
• DOCUMENTATION FIX: The theming guide has been overhauled. It’s now linked from Setup
: Wizards (just like all the other manuals.)
• CHANGE: The “Incident Note” feature has been removed. It cluttered the interface and is
almost useless in CanIt-PRO and Domain-PRO.
• CHANGE: Internally, we use Mail::SPF rather than the deprecated Mail::SPF::Query to handle
SPF lookups.
287
• POLICY CHANGE: When looking for SPF scoring rules, we recursively strip off domain components in the same way as for Domain Action rules.
• IMPROVEMENT: There is no need to manually create and maintain a script to synchronize
Bayes data files. Instead, the CanIt cluster system automatically synchronizes Bayes data to all
scanners.
• IMPROVEMENT: The text of the “Periodic Report” e-mail can be templated.
• IMPROVEMENT: We tokenize the “HELO” string for Bayes.
• MAJOR INTERNAL CHANGE: The internal mechanism used to run tasks across cluster members has been drastically overhauled and should be much more robust.
• PERFORMANCE IMPROVEMENT: CanIt can now use the PgBouncer connection pooler to
reduce load on the database. PgBouncer is packaged for our Debian-based appliances.
• PERFORMANCE IMPROVEMENT: We use the “CDB” database format for storing Bayes
data rather than Berkeley DB. CDB should be faster than Berkeley DB and the files are portable
across operating systems and CPU architectures.
• IMPROVEMENT: If a message is oversize, we attempt to scan it anyway after removing nontext parts. (If the remaining text parts are still oversize, we do not scan the message for spam.)
This should help considerably in catching spams that are artificially inflated with image attachments.
• BUG FIX: CanIt is now compatible with PostgreSQL 8.4.0.
• BUG FIX: The “Bogus MX” check now considers 0.0.0.0 to be bogus.
• BUG FIX: A performance regression when viewing very large traps has been fixed.
• BUG FIX: Crash-inducing typos in the SPF Rules page and the daily-mail-by- realm report have
been fixed.
• NEW FEATURE: Sessions can be made to last longer than 8 hours with the new “Remember
Me” checkbox on login screen. (Default Remember Me time is one week.)
• NEW FEATURE: The POP3, IMAP and Program external authentication methods let you strip
the domain name from the login name to generate the home stream. For example, you can
configure it so that “[email protected]” is placed in a home stream called “user”.
• NEW FEATURE: An administrator (or realm administrator) can choose to allow sender
whitelisting/blacklisting directly from notification messages. The administrator can also set
the default pulldown settings in notification messages to “Reject” or “Do nothing”.
• NEW REPORT: An administrator (or realm administrator) can pull a report showing the number
of addresses seen per stream.
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• IMPROVEMENT: In the “Clickable Webform” notification, clicking on the message subject
displays the message body without requiring logging in.
• CHANGE: canit-storage-manager has an official IANA port number (6568). The default port
has been changed to reflect that.
• FIX: The 70 sare stocks.cf ruleset is obsolete and has been deleted.
• BUG FIX: The API server would sometimes return a 500 error code instead of a 404 not found
code.
• BUG FIX: If an incoming message has an X-Spam-Flag: header, we delete it.
• BUG FIX: /etc/init.d/canit-system behaves more reliably if the database happens to be down
when it is run.
• BUG FIX: When we download a new ruleset, we now signal all scanners to re-read the rules
files.
• BUG FIX: Several other minor bugfixes and cosmetic improvements.
• UPDATES: Updated to MIMEDefang 2.68 and ClamAV 0.95.1.
• PERFORMANCE IMPROVEMENT: When using Embedded Perl, scanner startup time is improved. Also, more memory can be shared among scanners, reducing the total memory footprint.
• IMPROVEMENT: In CanIt 6.0.0 and 6.0.1, incidents that expired out of the trap were never
counted in daily statistics. Now they are counted in their own category (“Expired from Trap”)
• PERFORMANCE IMPROVEMENT: Performance of greylisting was improved on large and
busy clusters by partitioning the greylisting table in the database.
• POLICY CHANGE: If the score for AutoRejectNoIncident is lower than AutoReject, we increase it to match AutoReject.
• IMPROVEMENT: canit-prepare-system warns if it notices that SELinux is enabled. It also sets
reasonable defaults for mx maximum in canit.conf.
• NEW SETTINGS: canit.conf has new settings in the [mimedefang] section: conserve descriptors, md required fds and mx required fds. See /usr/share/canit/canit.conf for details.
• BUG FIX: Several typos in the HTML manuals were fixed.
• BUG FIX: The address-count-by-domain report used SQL that didn’t work on old versions of
PostgreSQL; this has been fixed.
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• BUG FIX: The Domain Setup Wizard would refuse to let you choose “Other” for the streaming
method; this is fixed.
• BUG FIX: A minor rendering error on the Bayes Rules page was fixed.
• BUG FIX: The “Bulk Entry” page performs basic validation of entered data.
• BUG FIX: A bug in the Storage Manager Wizard that would only let you change one host’s
Storage Manager Settings has been fixed.
• BUG FIX: PDF pie charts would render incorrectly if there were many entries; this has been
(partially) fixed so that even if some entries are truncated, the pie graph displays correctly.
• BUG FIX: The “PhishingAddress” test worked, but put a nonsensical value in the list of fired
test names. This has been fixed.
• NEW FEATURE: CanIt can produce reports showing the number of valid e-mail addresses seen
per domain (and per-realm, for CanIt-Domain-PRO.)
• BUG FIX: In certain very unusual situations, the database upgrade script could abort. This has
been fixed.
• BUG FIX: The Storage Manager wizard in 6.0.0 did not work correctly with multiple storage
manager nodes; this has been fixed.
• BUG FIX: If you create a periodic report with no charts, CanIt used to produce invalid PDF.
Now, it produces a single-page PDF containing an error message.
• BUG FIX: On new installations only, the RunBayesJournal background task would die. This
has been fixed.
• BUG FIX: A typo in version 6.0.0 would sometimes cause a filtering process to terminate abnormally. This has been fixed.
• BUG FIX (CanIt-Domain-PRO only): Deleting a realm would sometimes leave some realm
data in the database. Now, it is all cleaned out.
• BUG FIX: Reports now have fields for realms and streams, rather than Yes/No fields “Show All
Realms” and “Only This Stream”.
• BUG FIX: Non-root users could not create periodic reports; this has been fixed.
• BUG FIX: Under VMWare, the master multiplexor process could consume a lot of CPU time.
This has been fixed (but we still do not recommend running CanIt under VMWare, especially
the PostgreSQL database server.)
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• UPGRADE NOTE: It is no longer possible to upgrade versions of CanIt less than 4.0.0 to the
current version. If you are running CanIt older than 4.0.0, you must first upgrade to 5.0.2 before
upgrading to 6.0.0.
• NEW FEATURE: CanIt blocks mail to or from addresses on a dynamically-maintained phishing
address list. This list is distributed several times a day over the RPTN distribution channel.
• NEW FEATURE: On an emergency, per-domain basis, you can block Delivery Status Notifications to cope with severe backscatter. (This feature is dangerous, so must be explicitly enabled
under Setup : Features)
• NEW FEATURE: CanIt can generate and e-mail PDF reports on a periodic basis. You can
configure which reports you want and how often you want to receive them.
• POLICY CHANGE (Appliance Only): If your sources.list file contains a non-RoaringPenguin
repository, automatic updates are suppressed; you have to run the update manually in this case.
• POLICY CHANGE: The nightly RPTN download submits some statistics back to the RPTN
server for Roaring Penguin’s monitoring and analysis purposes. In particular, it submits the
PostgreSQL version, license key, operating system name and version, CanIt version, count of
number of hosts in your cluster, count of number of valid inbound email addresses and domains
seen in the last 60 days, and daily cluster load statistics. No personally-identifying information
is reported back.
• PERFORMANCE IMPROVEMENT: If you are using Storage Manager, we do not store anything in PostgreSQL for a Bayes signature unless it is trained. On busy systems, this can considerably reduce the load on the database.
• BUG FIX: Fixed some rendering errors in the Web interface on Opera and Chrome.
• BUG FIX: RPTN downloads now validate the server certificate against Roaring Penguin’s certification authority file.
• BUG FIX: The Storage Manager Wizard is better integrated with the Cluster Management GUI.
• BUG FIX: canitd, the CanIt Daemon, has been completely rewritten to improve reliability.
• BUG FIX: You can now specify a port number if PostgreSQL is listening on a non-standard
port.
• BUG FIX: Silenced annoying (but harmless) log messages about duplicate keys from the
LogLoad daemon task.
• MAJOR POLICY CHANGE: Self-whitelists are ignored. That is, if the sender e-mail address
is the same as the recipient e-mail address, any whitelist for that address is ignored. Similarly,
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if the sender domain is the same as the recipient domain (or a subdomain thereof), then any
domain whitelist is ignored.
• NEW RULES: We ship a SpamAssassin plugin that detects many kinds of targeted phishing
attempts (known as “spear phishing”). Look for the RP PHISH rule in incident reports.
• PERFORMANCE IMPROVEMENT: Performance of Bayes training SQL queries has been improved.
• IMPROVEMENT: We do not auto-whitelist messages if the outgoing message looks like an
out-of-office auto-reply.
• BUG FIX: “Import Rules” did not correctly import rules exported by “Export Rules”; this has
been fixed.
• BUG FIX (Domain-PRO only): Only the site administrator can switch into the special “@@”
streams (which are always in the base realm.)
• BUG FIX: The MIMEDefang SNMP agent reported inaccurate data; this has been fixed.
• BUG FIX: If the master “canitd” daemon lost connection with the PostgreSQL database, it
would incorrectly stop various daemon tasks. This has been fixed.
• BUG FIX: Under certain circumstances, CanIt would inappropriately store an additional copy
of released messages. This has been fixed.
• BUG FIX: (Appliance Only) Automatic upgrades were broken in 5.0.1; they are fixed in 5.0.2.
(Note that we released interim 5.0.1 packages that fixed the problem also, so very few appliances
should be affected.)
• BUG FIX: The Sendmail address mapper Path in the database was not updated to reflect the
new location of sendmail-account-info.pl. It is now.
• NEW RPMS: We now supply RPMs for Fedora 10 on i386. NOTE: This will be the LAST
version of Fedora for which we will supply RPMs. For future Fedora releases, you will need to
install CanIt from source.
• UPDATE: ClamAV updated from 0.94.1 to 0.94.2.
• IMPROVEMENT (Appliance Only): The upgrade process on appliances has been improved;
e-mail notifications are more meaningful. You can configure Automatic vs Manual upgrade via
the Web interface. The system will refuse to do automatic upgrades on a cluster.
• COSMETIC IMPROVEMENT: If the geolocation code cannot determine the location of a relay,
a special small flag is shown rather than “Location Unknown”.
• BUG FIX: The RPMS for Red Hat Enterprise Linux 3 did not work because of the ancient
version of Perl on RHEL3. We have since made the code work.
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• BUG FIX: The “Reset Inheritance” button for stream settings did not work in 5.0.0. It now
works as designed.
• BUG FIX: We inadvertently used a PHP function only available in newer versions of PHP. This
broke some reports. We’ve fixed the code to use functions available in all supported versions of
PHP.
• BUG FIX: The sanity-checker emitted false reports of failed ticker tasks. This has been fixed.
• BUG FIX: New cluster members automatically register themselves as scanners. While this may
not always be the case, it almost always is and is a better default behaviour.
• BUG FIX: The country-name selection menu on the Rules : Countries page was too narrow in
Internet Explorer. This has been fixed.
• BUG FIX: The CanIt API server would ignore realm restrictions for certain stream-listing
queries. This has been fixed.
• BUG FIX: Advanced Search would sometimes double-escape input data, leading to failed
searches that really should have succeeded.
• BUG FIX: Various minor PHP and JavaScript warnings have been fixed.
• MAJOR NEW FEATURE: CanIt determines the country in which a sending relay is located.
You can make rules based on sending country; geolocation information is also used as Bayes
tokens.
• MAJOR NEW FEATURE: Cluster management has been completely revamped. It is much easy
to set up a cluster now.
• MAJOR NEW FEATURE: The cluster-management system collects performance data for all
scanners in the cluster; the Web interface lets you plot the data minute-by-minute, hour-by-hour
or day-by-day.
• MAJOR NEW FEATURE: CanIt can do dictionary-attack detection and block abusive hosts at
the firewall level. This feature is ONLY available on Linux.
• MAJOR NEW FEATURE: The Web interface includes a Domain Setup Wizard that walks you
through all the major steps required to set up a new domain.
• NEW FEATURE: You can set expiry dates on most rules. This lets you avoid “rule creep” as
many rules accumulate and last forever.
• NEW FEATURE: The Administration Guide and Users Guide are available in HTML format.
Most CanIt GUI pages link to corresponding manual sections.
• NEW FEATURE: Auto-whitelists now expire (by default after 180 days).
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• NEW FEATURE: SNMP tools are packaged with CanIt. Note that you need to install and
configure net-snmp yourself to enable the SNMP tools.
• IMPROVEMENTS: Many additional reports were added; existing reports were made more configurable.
• MAJOR IMPROVEMENT (Appliance Only): The text-based interface for setting up a CanIt
appliance has been completely rewritten and is much more usable and stable.
• MAJOR IMPROVEMENT: Sender and Domain rules work both with the SMTP envelope
sender and the address in the From: header. The previous behaviour of ignoring From: was
very confusing to end-users.
• MAJOR IMPROVEMENT: The “sanity checker” that checks for common misconfigurations
has been revamped. It now e-mails the CanIt administrator if it discovers problems.
• MAJOR CHANGE: The “ticker” is gone. Replacing it is the CanIt daemon “canitd” that runs
on all hosts in a cluster.
• MAJOR IMPROVEMENT: The different CanIt startup scripts have been unified into
/etc/init.d/canit-system which starts or stops all processes required on a particular node.
• IMPROVEMENT: You can set “Allow Unauthorized Voting” on a per-stream (hence per-realm
in Domain-PRO) basis.
• POLICY CHANGE: SURBL is now charging large users for access to SURBL data. Please
read the comments in /etc/mail/spamassassin/72 score compensate.cf. Similar comments apply
to the URIBL.COM URI blocklist.
• POLICY CHANGE: Support terms have been changed. We have increased our excess support
fee from $75/hour to $100/hour, and have added the following clause:
After Hours Support: If mail delivery is interrupted, we reserve the right to make minimal
changes to get mail flowing again (including disabling filtering entirely) until our normal office
hours, at which time we will attempt to make a complete correction.
• POLICY CHANGE: By popular demand, the “Whitelisted Action” for filenames and extensions
also applies if a domain or host is whitelisted, and not only if an actual sender is whitelisted.
• POLICY CHANGE: We avoid greylisting very large messages (to conserve bandwidth)
• UPDATE: Updated ClamAV to version 0.94.1.
• CLEANUP: SpamAssassin rules shipped with CanIt were cleaned up and updated.
• CHANGE: The “Sendmail” address-mapping method has been removed. The upgrade process
replaces any Sendmail methods with an equivalent Program method.
• CLEANUP: Many global variables that had identical per-stream variables have been removed
(the globals were really only necessary for plain-CanIt and are not needed for CanIt-PRO or
CanIt-Domain-PRO.)
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• CLEANUP: Several global variables that were of marginal use have been removed and the
recommended behaviour has been hard-coded.
• CLEANUP: Many scripts and paths have been moved.
/usr/share/canit/scripts rather than in /etc/mail/canit.
We place most scripts under
• CLEANUP: The entire concept of “one-shot messages” has been removed. It was not useful
and served mostly to confuse.
• CLEANUP: “Hit-and-Run” is now consistently referred to as “Greylisting” to keep in line with
standard terminology.
• IMPROVEMENT: The formerly-global ”Auto-populate pending notification addresses” is now
per-stream (therefore per-realm in CanIt-Domain-PRO.)
• IMPROVEMENT: The internal storage-manager code has been changed to make it easier to
add, remove and rename storage-manager nodes.
• MAJOR REORGANIZATION: Most configuration files (mimedefang.conf, db-settings, etc.)
have been reorganized into one master configuration file canit.conf.
• BUG FIX: Mail log rotation on Debian-based appliances has been fixed. Previously, logs could
be rotated twice in quick succession.
• OTHERS: Many other minor bug-fixes and improvements.
• UPDATES: Updated ClamAV from 0.93.1 to 0.93.3
• BUG FIX: The global setting ”Silently discard rejected messages rather than remailing with
ticker” was removed from the Web interface, but not from the filter code. On busy servers, this
could result in large queues on the ticker host and delays in remailing released messages.
• BUG FIX: A missing JavaScript check on one of the “Reject All as Spam” buttons in the trap
display was fixed.
• BUG FIX: The CanIt Domain Routing API call would fail if you supplied only one server for
domain routing. This has been fixed.
• UPDATES: Updated SpamAssassin from 3.2.3 to 3.2.5. Update ClamAV from 0.92.1 to 0.93.1.
Some clamd options have been removed; you MUST remove them from your clamd.conf file or
clamd will refuse to start. (CanIt appliances will automatically remove the options.)
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The options to remove are:
ArchiveMaxFileSize, ArchiveMaxRecursion, ArchiveMaxFiles, ArchiveMaxCompressionRatio and ArchiveBlockMax
• POLICY CHANGE: On new installations, the default for “Tempfail Suspect Messages” is now
“Never” rather than “Until-Dispatched”. We decided the change was necessary to avoid amplification effects on very busy systems and to avoid support queries when people release mail
after several days.
• NEW BINARY PACKAGES: We have added support for Fedora 9 RPMs on i386. We have
dropped binary packages for Fedora Core 5 and 6.
• IMPROVEMENT: We have provided a new command-line tool called “canit-api-client”. You
should begin using it rather than “canit-cmd” because “canit-cmd” will be removed in CanIt
4.2.0.
• WORKAROUND: We implemented a workaround for Outlook 2007’s broken form-handling
behaviour; it lets you accept or reject individual messages from the notification e-mail.
• IMPROVEMENT (CanIt-Domain-PRO only): “Source Address of CanIt Notifications” and
“Full name for sender of CanIt notifications” can now be set on a per-realm basis.
• IMPROVEMENT: Global Settings and Stream Settings are now grouped into related sets. You
can hide the display of sets you’re not interested in seeing.
• IMPROVEMENT: If the DNS lookup to find the RPTN version fails, the System Check page
alerts the administrator.
• IMPROVEMENT: In the trap display, if you have accepted any messages but click “Reject All
as Spam”, CanIt prompts for confirmation first.
• WORKAROUND: If the system time on the ticker is set far in the future and then reset to the
correct time, ticker tasks may not run. The ticker code now detects clock skew and compensates
for it.
• IMPROVEMENT/BUG FIX: The API server has had many validation bugs fixed.
• BUG FIX: The PostgreSQL failover module has been update with various bug fixes as well as
a workaround for bugs in PostgreSQL 8.3.0 and 8.3.1.
• BUG FIX: If the database is still starting up, the CanIt Storage Manager startup script keeps
trying for a while before giving up.
• BUG FIX: A quoting error in decoding certain encoded subject lines has been fixed.
• BUG FIX: The Authentication Mapping web page did not handle a Filter correctly. This is now
fixed.
• BUG FIX: The “Dashboard” Web page did not respect all permissions correctly. This is now
fixed.
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• BUG FIX: The ForceToStream attribute is ignored for mail originating from the loopback address. The old behaviour would sometimes cause released mail to be re-trapped in a different
stream.
• BUG FIX: CanIt would sometimes leave SpamAssassin temporary files littering /tmp; this has
been fixed.
• WORKAROUND: “Clickable Webforms” do not work with Outlook 2007 and cannot be made
to work; we added a note to that effect for Outlook 2007 users.
• COSMETIC FIX: The “View System Load” button on the Server Management page was absurdly big. It now matches the other buttons.
• BUG FIX: If users defaulted to the “Simplified Interface”, the RSS feed did not work. This is
now fixed.
• BUG FIX: Templates for “Clickable Webform” pending notifications were not being set correctly. This is now fixed.
• BUG FIX: Pending Messages were not being triggered as incidents were created. This is now
fixed.
• BUG FIX (Domain-PRO only): “Clickable Webform” sometimes did not work, depending on
which realm the user was in. This is now fixed.
• BUG FIX: Updating Templates didn’t take effect immediately; this is now fixed.
• BUG FIX: The canit-cmd tool and the API server would not let you set the treat as mx flag for
verification servers. This is now fixed.
• BUG FIX: The API server did not work on some versions of Red Hat because Red Hat ships a
truly ancient version of Sys::Syslog. We have worked around the problem.
• BUG FIX: We inadvertently packaged the wrong version of the PostgreSQL failover code. This
has been fixed.
• MAJOR NEW FEATURE: Users can configure an RSS feed of pending incidents. This allows
you to use your favourite RSS feed reader to monitor your trap.
• MAJOR IMPROVEMENT: Pending notifications are only sent out if there are new pending
messages. Also, you can configure notifications to be submittable forms; this allows you to
accept or reject messages directly from your e-mail client without having to authenticate with
CanIt.
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• IMPROVEMENT: You can restrict the days on which Pending Notifications are sent. (You can
skip them on weekends, for example.)
• IMPROVEMENT: We use the creation date of an incident when logging it in the statistics tables
rather than the resolution date. However, pending incidents that are resolved some time after
they are created appear only in daily statistics, not hourly statistics.
• NEW FEATURE: You can set the full name for the source of CanIt notifications.
• IMPROVEMENT: CanIt can be disabled for maintenance from the Web interface. You no
longer have to create /etc/mail/canit/disabled on all machines.
• POLICY CHANGE: We have disabled all spamhaus.org DNS-based RBLs. Spamhaus is becoming more adamant about enforcing its terms-of-use; if you wish to use Spamhaus-based
tests and do not qualify for free use of the RBLs, please arrange directly with Spamhaus for a
data feed contract.
• POLICY CHANGE: We have removed the Sendmail domain-mapping method. The upgrade
script replaces it with a Program method for backward-compatibility.
• PERFORMANCE IMPROVEMENT: Marking old incidents as spam has been moved out of the
cron job into a ticker task that can operate more leisurely.
• PERFORMANCE IMPROVEMENT: If a stream has too little Bayes training, we don’t use that
stream’s training database. (Before, we’d add the database totals together and if the total was
large enough, we would use all the data.) This greatly improves performance on sites with many
streams where most of the streams have little Bayes data.
• IMPROVEMENT: Log the IP address of HTTP clients in incident logs.
• IMPROVEMENT: The site administrator can temporarily disable pending notifications.
• SECURITY IMPROVEMENT (CanIt-Domain-PRO only): Only the super-root can create “Program” or “Program Legacy” user-lookups.
• GUI IMPROVEMENT: The GUI prompts for confirmation before deleting rules, users, etc.
• UPDATES: Update to ClamAV 0.92.1 and Net::DNS 0.63.
• BUG FIX: Fix internal handling of “duplicate key violation” error message from PostgreSQL
8.3.
• BUG FIX: Various bugs in the CanIt-API server were fixed.
• BUG FIX: Build problem on NetBSD and FreeBSD was fixed.
• BUG FIX: Under certain conditions, CanIt would break S/MIME signed messages. This has
been fixed.
• BUG FIX: Storage-manager startup script incorrectly distinguished upper- and lower-case in
host names. This has been fixed.
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• BUG FIX: Prohibit deletion of @@READABLE and @@WRITABLE permission-sets (in base
realm only in CanIt-Domain-PRO.)
• BUG FIX: The PHP code would fail if one Storage Manager node was marked read-only. This
has been fixed.
• BUG FIX (CanIt-Domain-PRO only): Invalid recipients would always be logged in the “base”
realm’s statistics instead of the correct realm. This has been fixed.
• NEW FEATURE: You can enter multiple verification servers (separated by commas) for a given
domain. CanIt tries the servers in order until it receives a definite success or failure indication.
• NEW FEATURE (CanIt-Domain-PRO only): The site administrator can view statistics aggregated across all realms.
• CHANGE: We emit key/value logging information when an incident is held or streamed.
• POLICY CHANGE: All of the products (CanIt, CanIt-PRO and CanIt-Domain-PRO) now use
the same filter file.
IF YOU HAVE MODIFIED YOUR FILTER FILE, BE SURE TO TEST YOUR MODIFICATIONS WITH THE NEW FILTER BEFORE INSTALLING ON A PRODUCTION SERVER.
If you have not modified your filter file, an upgrade will proceed safely.
• PERFORMANCE IMPROVEMENT: If you use Storage Manager, the expiry job prunes
storage-manager data in the background.
• BUG FIX (Standard CanIt only): The displayed RPTN statistics would be incorrect if local
Bayes training occurred. This has been corrected.
• BUG FIX: A PHP warning on the Reports page was corrected.
• BUG FIX: Some minor CSS settings were updated to work better with Internet Explorer.
• BUG FIX: Some minor bugs in the CanIt API and canit-cmd were fixed.
• BUG FIX: Errors in rendering pie charts with very small wedges were corrected.
• BUG FIX: The upgrade code from CanIt to CanIt-PRO would fail to initialize some CanIt-PRO
templates; this has been fixed.
• NEW PACKAGES: We have Debian packages for Etch as well as sarge, and a new Etch-based
ISO image.
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• NEW FEATURE: The “Stream Settings” page can show where each setting comes from (in
other words, which stream it is inherited from.)
• PACKAGING IMPROVEMENTS: Several formerly appliance-only features such as PostgreSQL failover and configuring mail routing from within the CanIt web interface are now
available in the RPM versions.
• BUG FIX: The file wal archive command.pl was inadvertently left out of the failover packages;
this has been corrected. Additionally, we include a sample failover configuration file.
• BUG FIX: The charts in the Statistics page were adjusted to avoid cutting off Y-axis labels.
• BUG FIX (CanIt-Domain-PRO only): The Known Networks page would insist on an entry in
the force-to-stream column even if you didn’t want one. This has been fixed.
• BUG FIX: Storage Manager would not compile on some old C compilers. This has been fixed.
• BUG FIX: The index on the daily statistics table was suboptimal, leading to slow queries. This
has been fixed.
• BUG FIX: The Stream Permission page did not expand/contract properly under Internet Explorer. This has been fixed.
• NEW FEATURE: A stream setting can limit the maximum number of entries in the Valid Recipients Table. By removing permissions from this entry, a site administrator can limit the
maximum number of valid recipients per stream.
• NEW FEATURE: A verification server can listen on a non-standard port; use “servername/port”
in the Verification Server table.
• EXPERIMENTAL FEATURE: We calculate Bayes probability based on the Robinson-Fisher
calculation. This calculation is not used, but information about it appears in headers and reports.
More testing is needed to see if the Robinson-Fisher calculation is actually any better than the
Naive Bayes calculation.
• POLICY CHANGE: The main Reports page now shows statistics for all streams if the user has
root privileges. Unprivileged users only see statistics for their particular stream.
• IMPROVEMENT: The canit-convert-statistics.pl script now works with standard CanIt as well
as CanIt-PRO and CanIt-Domain-PRO.
• BUG FIX: On standard CanIt appliances, we accidentally
Log::Syslog::Abstract module. It is now correctly included.
omitted
the
Perl
• BUG FIX: Fixed compilation failure of canit-storage-manager on FreeBSD 5.0.
• BUG FIX (Domain-PRO only): The web interface insists on a fully-qualified stream name for
the “Force-to-Stream” attribute.
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• BUG FIX: On *new* installations only, the init-database script did not create /etc/mail/canit/dbsettings. This is now fixed.
• BUG FIX: The CanIt REST-based API did not return the same information for list-activestreams as the Web interface. This has been fixed.
• MAJOR NEW FEATURE: Statistics and reporting have been completely reworked. There are
many more reports available and if your PHP installation has the GD extension, you get graphical charts.
• MAJOR NEW FEATURE: We have scripts for automatic database failover using PostgreSQL’s
Point-in-Time-Recovery feature. The failover feature is only available on our Debian-based
appliances, however.
• MAJOR ARCHITECTURAL CHANGE: CanIt includes a dedicated “Storage Manager” daemon for storing large blocks of textual data. This cluster-aware daemon greatly relieves the
load on the PostgreSQL database. It should considerably shrink the size of the database, with
attendant improvements in expiry, VACUUM and dump times and overall performance.
• MAJOR NEW FEATURE (PRO and Domain-PRO only): The command-line tool has been
replaced with a completely-new REST-based API. (We ship a replacement command-line tool
that uses the REST API rather than direct database manipulation.)
• NEW FEATURE (Appliance Only): You can specify that the appliance is to treat a name in the
domain routing table as an MX record rather than a host name. This allows for load-balancing
back-ends servers using DNS.
• NEW FEATURE: Each stream can request mail to be blind-carbon-copied to an additional email address.
• NEW FEATURE: We have implemented a mechanism similar to RPTN for automatically pushing out SpamAssassin rules.
• NEW FEATURE: The cron job can be configured to rotate nightly dumps, keeping a configurable number of nightly dumps.
• NEW FEATURE: “Known Networks” has been enhanced to include a pseudo-network called
“SMTP-AUTH”. Settings for that network apply to senders who authenticate using STMP
AUTH.
• NEW FEATURE: A ’*’ entry in the domain for a verification server acts as a wildcard. Do not
use this feature if your CanIt server relays outbound mail!
• NEW FEATURE: You can specify how many hours to keep mail in ”Current Statistics.” The
default setting of three days is much too long on very busy mail servers.
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• UPGRADES: Upgraded bundles software: SpamAssassin from 3.1.8 to 3.2.3; ClamAV from
0.90.3 to 0.91.2.
• PACKAGING CHANGES: We have added packages for Fedora 7. We have dropped binary
packages for Solaris, Fedora Core 3 and Fedora Core 4. You will need to install from source on
those platforms.
• GUI IMPROVEMENT: Release notes and all PDF manuals are accessible from the Web interface.
• GUI IMPROVEMENT: The “System Check” page has been improved to show the results of all
system tests. It also shows the currently-loaded RPTN and ruleset versions.
• IMPROVEMENT: We tokenize additional parts of messages for Bayes, such as the sending
relay and the local and domain parts of the envelope sender.
• UPDATE: Removed “Chickenpox” SpamAssassin rules.
• CHANGE: All relics of the old CanIt-SMB codebase have been removed and consolidated into
CanIt-PRO.
• GUI CHANGE: Web pages are rendered in UTF-8 rather than ISO-8859-1 character set.
• CHANGE: The X-Antispam-Training headers are renamed to X-Antispam-Training{Forget,Nonspam,Spam}. Some marginal mail clients seem to delete multiple headers with
the same name.
• MINOR IMPROVEMENT (PRO, Domain-PRO only): Administrators can sort incidents by
stream when viewing the “*” pseudo-stream.
• GUI IMPROVEMENT: The GUI character set is now UTF-8. This should allow for more
accurate display of message subjects in non-Western character sets.
• MINOR IMPROVEMENT: The X-Bayes-Prob header now lists which streams’ tokens were
used. This makes it easier to verify that RPTN is being used.
• MINOR IMPROVEMENT: The sample script for synchronizing Bayes databases uses the -S
and -O options with rsync (if your version of rsync supports them.)
• MINOR IMPROVEMENT: The administrator can set the “Forgot your Password?” link from
Setup : Templates.
• RULE CHANGE: Removed the VIRUS WARNING64 SpamAssassin rule which could cause
false-positives.
• BUG FIX (appliances only): You could not edit a domain-routing entry. (You would have to
delete/add it). Editing now works properly.
• BUG FIX (PRO, Domain-PRO only): Editing an Address Mapping in the Web interface now
explicitly clears the “cached” flag.
302
• BUG FIX: The BccAddress stream permission was not correctly granted by a database upgrade.
Now fixed.
• BUG FIX: Obsolete settings are now correctly deleted from the setting desc table upon database
upgrade.
• BUG FIX: The attachment-stripping code would sometimes log a filename of “unknown” rather
than the proper filename.
• BUG FIX: The watch-clamd script uses a lock to prevent two concurrent instances.
• BUG FIX: The “Domain Rules” page accepts top-level domains like “jp” or “ca” without complaining that they are invalid.
• BUG FIX (Debian appliances only): Ownership and permissions of /var/lib/clamav have been
fixed.
• BUG FIX: The incident creation code has been cleaned up to reduce the chance of race conditions.
• BUG FIX (Plain CanIt only): If RPTN downloads are disabled, do not use RPTN data (it is
probably stale anyway.)
• BUG FIX: Sendmail accepts addresses like <[email protected]> and
<\d\f\[email protected]> equivalently. This can mess up AsIs or ChopDomain
streaming, so CanIt canonicalizes addresses by removing backslashes.
• BUG FIX: The Simplified Interface is disabled if you’re in the “default” stream. (Before, it
would appear but do nothing because default’s inheritance cannot be changed.)
• BUG FIX: In several places in the Web interface, potentially-dangerous actions were performed
by a GET request. These have all been converted to POST to make it difficult to accidentally
bookmark a dangerous request.
• BUG FIX: The “WHOIS” page would sometimes lose the “s=xxx” parameter in the URL, causing it to refuse to send abuse complaints. This has been fixed.
• BUG FIX: If “One-Shots” are disabled, the Show Active Streams page no longer has a One-Shot
column.
• BUG FIX: Generating the “Hit-and-Run” report could consume huge amounts of memory causing PHP to abort. This has been fixed.
• BUG FIX: We test mail against a Verification Server before attempting to stream it. This can
reduce load considerably in some configurations.
303
• ENHANCEMENT: Hit-and-Run detection now takes into account mutating message subjects,
making greylisting even more effective.
• UPGRADE: Packaged version of ClamAV has been upgraded to 0.90.3.
• GUI ENHANCEMENT (Appliance Only): The Domain Routing page has a Filter box that lets
you limit which domains are displayed.
• GUI ENHANCEMENT: The message display page makes better use of screen real-estate to
reduce back-and-forth scrolling.
• POLICY CHANGE (PRO and Domain-PRO only): We now do greylisting (AKA Hit-and-Run
Detection) before streaming. If a message comes in for more than one stream, and *all* of the
streams have greylisting enabled, we greylist the message.
• POLICY CHANGE (PRO and Domain-PRO only): Greylisting applies even to opted-out
streams. (However, since you can now disable greylisting on a per-stream basis, you can turn
off greylisting for opted-out streams if you wish by explicitly disabling greylisting.)
• BUG FIX: The RPTN download task obeys proxy settings in environment variables. (See the
LWP::UserAgent man page for details.)
• MINOR ENHANCEMENT: The message display page displays only the main headers (ReturnPath, From, To, Subject and Data) by default, with a JavaScript link to reveal/hide all headers.
If you have re-themed CanIt, please test your theme. The base theme now uses an external
JavaScript library rather than emitting inline JavaScript. If your themes inherit from rather than
replace our themes (the recommended approach), they will most likely work fine.
• BUG FIX (PRO and Domain-PRO only): If an attachment is stripped from an e-mail that has
no text/plain or text/html parts, we add the notice of stripping as a separate text/plain part.
• BUG FIX (PRO and Domain-PRO only): Parameter validation was improved; previously, a
stream named “0” was not allowed.
• BUG FIX (PRO and Domain-PRO only): If a stream inherited from another stream, the inheriting stream’s owner could get spurious Pending Notifications. This has been fixed.
304
ON SOURCE AND RPM INSTALLATIONS, YOU MAY NEED TO EDIT clamd.conf AND
freshclam.conf. THE SYNTAX HAS CHANGED. Instead of single words like “LogSyslog”, you must now use “LogSyslog Yes”. PLEASE VERIFY YOUR CLAM CONFIGURATION FILES AFTER UPGRADING. See http://wiki.clamav.net/Main/
UpgradeNotes090 for details
On our Debian-based CanIt appliances, the upgrade script will fix the Clam configuration files
automatically.
• MINOR CLEANUP: The cron job removes its lock file when it has finished. There is no harm
from leaving the lock file lying around, but it is cleaner to remove it.
• BUG FIX: All hard-coded colors in the PHP code have been eliminated in favour of CSS
stylesheets and classes.
• BUG FIX: A typo in the PHP code could produce a PHP warning; this has been fixed.
• BUG FIX (CanIt-PRO and higher only): Inheritance of the “Use Simplified GUI” preference
was broken; it is now inherited just like other preferences.
• BUG FIX (CanIt-PRO and higher only): A User Lookup would not accept a comma-separated
list of servers unless there was whitespace around each comma. This has been fixed so the
whitespace is allowed but not required.
• BUG FIX (CanIt-PRO and higher only): The “Filter” on the Inheritance page now filters both
by stream and inherited-stream.
• BUG FIX (CanIt-Domain-PRO only): If you deleted a realm mapping, some settings for a
domain (Verification Server, Authentication Mappings and Domain Mappings) would be “orphaned”. Now, they are moved into the new realm that contains the domain.
• NEW ARCHITECTURE: We now have RPM packages for Red Hat Enterprise Linux 5
• BUG FIX: The VACUUM and database backup cron jobs would fail on password- protected
databases. They now work correctly.
• BUG FIX: When Bayes votes were acted upon, CanIt forgot to record the vote in the Bayes
signature table (although it did correctly update the Bayes statistics.) The vote is now properly
recorded.
• BUG FIX (CanIt-PRO and higher only): The Web interface and Perl code disagreed about the
default value for “Permit use of auto-whitelisting”. They are now in agreement.
305
• BUG FIX: The cron script would sometimes fail to find required Perl modules on Solaris, and
the locking mechanism would fail on Solaris, Both of these problems have been fixed.
• BUG FIX: When switching streams after doing an Advanced Query, the query would be forgotten. It is now correctly remembered.
• BUG FIX (CanIt only): Some PHP pages such as Bayes Settings would fail to render on Standard CanIt. This has been fixed.
• BUG FIX: The host IP in the Report pages did not link to a proper WHOIS query URL. This
has been fixed.
• NEW FEATURE: When you create an LDAP user-lookup, you can specify a connect timeout
for streaming. (The timeout does not apply to authentication because PHP unfortunately lacks
a mechanism to specify the timeout.)
• TRANSLATION IMPROVEMENT: The French and Spanish translations have been updated.
• BUG FIX: The RPM installer correctly recognizes all versions of CentOS 4.
• BUG FIX: Some architecture-specific Debian packages were incorrectly marked “all”. They
are now marked “i386” as they should have been.
• BUG FIX: Hit-and-run statistics could be incorrect depending on your greylisting settings. This
has now been fixed.
• BUG FIX: On some versions of DBI and PostgreSQL, the expiry job could fail with a bunch of
SQL syntax errors being emitted. This has been fixed.
• BUG FIX: When verifying RPTN signatures, gpg would sometimes warn about insecure memory. This warning has been suppressed.
• BUG FIX: In the 3.4.x series, whitespace was stripped from the beginning and end of all form
entries. If your password began or ended with a space, this would make logging in impossible.
3.4.2 no longer strips spaces from password-entry boxes.
• BUG FIX: Entering a blank or non-numeric score for an RBL rule would cause a PHP error.
• BUG FIX: Upgrading from CanIt to CanIt-PRO could fail when updating the Bayes table. This
has been fixed.
• BUG FIX: Some missing “NOT NULL” column constraints were added.
• BUG FIX: A useless warning “Non-multipart entity with no bodyhandle??” would sometimes
appear in the mail logs; this has been removed.
• BUG FIX: Warnings about undefined variables if a sender is whitelisted due to SMTP AUTH
have been suppressed.
306
• BUG FIX: Fix a bug in the database upgrade code which could make the schema upgrade fail.
• BUG FIX: Remove a harmless but annoying PHP warning from the trap display.
• MAJOR NEW FEATURE: The old “Access Rights” page is gone. In its place are far more
flexible “Permissions” pages. These allow fine-grained control over permissions on a per-user
and per-group basis. The database upgrade code should migrate the old Access Rights to the
new Permissions accurately.
• MAJOR CHANGE (CanIt-PRO and Domain-PRO only): The old “Stream Redirection” concept
is gone. In its place we have “Stream Inheritance”. This is more flexible and simplifies the code
a lot. The database upgrade code will migrate Redirection to Inheritance.
• MAJOR IMPROVEMENT (CanIt-PRO and Domain-PRO only): Hit-and-Run (also known as
“Greylisting”) can be enabled on a per-stream basis. However, greylisting is now always done
after the DATA phase of SMTP.
• GUI IMPROVEMENT (CanIt-PRO and Domain-PRO only): When you are viewing the ’*’
pseudo-stream, many things are writable (you can dispose of incidents, change rules, etc.)
• IMPROVEMENT (CanIt-PRO and Domain-PRO only): The canit-cmd command-line tool has
additional commands and is fully modular.
• PERFORMANCE IMPROVEMENT: A new caching scheme has reduced the number of
database queries per e-mail substantially, sometimes by more than 50%.
• PERFORMANCE IMPROVEMENT: Many internal code changes and code refactoring have
been performed to reduce memory usage and improve performance.
• NEW FEATURE: The Verification Servers feature allows you to queue mail (rather than tempfail it) if the verification server is unreachable. (The default is still to tempfail mail.)
• NEW FEATURE (CanIt-Domain-PRO Appliance Only): Realm administrators can set up mail
routing for domains within their realms.
• NEW FEATURE (CanIt-PRO and higher only): Locked Addresses can be locked to a commaseparated list of domains or addresses, any of which is permitted to send mail to the locked
address.
• GUI IMPROVEMENT: (Almost) any GUI page can be set as your default home page.
• GUI IMPROVEMENT: Layout of “Incident Details” page has been made much cleaner.
• IMPROVEMENT: Many more CanIt-generated messages are templatable so you can translate
them or tailor them to fit your site’s policies.
307
• IMPROVEMENT: The RBL timeout defaults to 7 seconds instead of 30 seconds and is configurable rather than hard-coded.
• POLICY CHANGE: CanIt’s “System Check” page warns if you do not enable RPTN downloads.
• POLICY CHANGE: The “Only See Spam” attribute has been removed from the Users table.
Instead, use the equivalent Permissions.
• POLICY CHANGE: We have removed support for a shared Bayes database in CanIt-PRO. It
complicated the code very much and never really worked well.
• POLICY CHANGE: Obsolete headers X-CanIt-Tag-Reason and X-CanIt-Warning are no longer
added. The information they would have contained is included in the X-Spam-Score header.
• POLICY CHANGE: Source packages no longer ship with Sendmail. You are expected to have
Sendmail and Milter installed as prerequisites.
• CHANGE: The canit.cron cron job is now written in Perl rather than Bourne shell.
• BINARY PACKAGES: We have added RPMs for Fedora Core 6 and dropped them for Fedora
Core 2.
• IMPROVEMENT: The GUI decodes base64- or quoted-printable-encoded subject lines.
• INCOMPATIBILITY: CanIt now requires PostgreSQL 7.3 or newer. It will NO LONGER
WORK with PostgreSQL 7.2.x or older!
• CHANGE: We no longer bundle Crypt-SSLeay with the source installer. You must install one
of Crypt::SSLeay or IO::Socket::SSL as a prerequisite for CanIt.
• IMPROVEMENT: More messages are templatable.
• IMPROVEMENT (Appliance Only): The GUI allows you to remove cluster members if you
remove or rename a node.
• IMPROVEMENT: The Advanced Search allows you to search by date range.
• BUG FIX: RPTN would sometimes fail GnuPG signature verification because of bad timestamps. This has been fixed.
• BUG FIX (CanIt only): RPTN data would not be reflected correctly in the Web interface. This
has been fixed.
• BUG FIX: All rules that can add to the score (Bayes, SPF, Mismatch) are now reflected in the
X-Spam-Score: header.
• BUG FIX: The LDAP user-lookup ignored the “Mail Attribute” setting when authenticating.
308
• BUG FIX (CanIt-Domain-PRO only): Realm-mapping lookups use the entire domain, then the
parent domain, and so on until a match is found. (For example, “foo.example.com” will search
the Realm Mapping Table for “foo.example.com”, “example.com” and “com” until it finds a
match.)
• BUG FIX (CanIt-Domain-PRO only): The command-line invocation “canit-cmd del-realm
REALMNAME” deletes all traces of a realm (including streams and users.)
• BUG FIX (CanIt-PRO and Domain-PRO): If you require streams to opt-in, then the database
upgrade script could opt-out the default stream. This has been fixed.
Appendix C
A Testing Topology for
CanIt-Domain-PRO
C.1
Introduction
The best way to evaluate CanIt-Domain-PRO is to route real-world mail through it. However, you
may be hesitant to place CanIt-Domain-PRO in production without testing it first. So we’ll show you
how to set up CanIt-Domain-PRO for test purposes, and then how to put it into production in a safe
way. The test topology makes it very easy to back out of CanIt-Domain-PRO if you decide to do so.
C.2
Assumptions
We make the following assumptions about your current e-mail setup:
• You already have a mail server that is your primary MX record, and you control that server and
its network. The existing mail server may run Sendmail, but it doesn’t have to—it could run
Netscape Messenger, Microsoft Exchange, or any other mail server software of your choice.
• You have a spare Intel-architecture server for installing Linux and CanIt-Domain-PRO. This
server should have sufficient horsepower to handle all of the mail for your domain or domains.
While you can use other supported UNIX operating systems for CanIt-Domain-PRO, the instructions in this paper are specific to Linux. If you are an experienced UNIX and Sendmail
system administrator, you can probably translate them for your own system.
• You control your DNS settings and can publish MX records for your domains.
C.3
Network Setup
Figure C.1 illustrates the assumed existing network setup followed by the new network setup. Note
that your actual setup may be more complex and may include firewalls, demilitarized zones, etc.
309
310
APPENDIX C. A TESTING TOPOLOGY FOR CANIT-DOMAIN-PRO
Conceptually, however, we assume you have an existing mail server which is the primary MX machine
for your domains, and which is connected to the Internet.
The test network shows how the CanIt-Domain-PRO server is configured to accept mail from the
Internet and relay it to your actual mail server.
Internet
Existing Mail Server
Original Network
Secondary MX
Primary MX
Internet
CanIt Server
Existing Mail Server
Test Network
Figure C.1: Network Configurations
C.4
Build the CanIt-Domain-PRO Server
To build the CanIt-Domain-PRO server, install Linux on an Intel Architecture server. Be sure to install
Apache, PHP and PostgreSQL, which are included with most Linux distributions. Alternatively, install
our Debian-based appliance build.
C.5
Configure the CanIt-Domain-PRO Server to Relay Mail
You’ll need to edit two files on the CanIt-Domain-PRO server to configure Sendmail to relay
mail. Make a list of all the domains for which your existing mail server accepts mail. Let’s
suppose you own the domains example1.com and example2.net, and accept mail for both on
the machine mail.example1.com. Finally, we’ll assume the CanIt-Domain-PRO server is called
canit.example1.com.
C.6. ROUTE TEST MAIL
C.5.1
311
Enable Relaying
First, you must enable relaying for the domains you control.
To do this, edit the file
/etc/mail/access and add a line for each domain, something like this:
To:domainname.tld
RELAY
In our example, we’d add two lines to /etc/mail/access:
To:example1.com
To:example2.net
C.5.2
RELAY
RELAY
Configure Forwarding Relays
Next, you have to tell CanIt-Domain-PRO where to relay mail for the domains. Edit the file
/etc/mail/mailertable and add a line for each domain, something like this:
domainname.tld
esmtp:[relay.domainname.tld]
In our example, recall that mail.example1.com handles mail for both domains, so our mailertable
would look like this:
example1.com
example2.net
C.5.3
esmtp:[mail.example1.com]
esmtp:[mail.example1.com]
Rebuild Sendmail Databases
Finally, you need to rebuild Sendmail’s internal databases to reflect these changes. Simply execute the
following Linux commands as root:
cd /etc/mail
make
C.6
Route Test Mail
Up until this point, your existing mail server has continued to act as it always does. The CanItDomain-PRO machine, although “live” and on the network, is not handling any mail traffic. Now
comes the time to route mail through the CanIt-Domain-PRO server. There are two options to route
test mail through the CanIt-Domain-PRO server:
312
C.6.1
Direct Injection
The least disruptive method is to directly inject test messages into the CanIt-Domain-PRO server. Run
an SMTP client and send messages via the CanIt-Domain-PRO server. Verify that they are received
and that spam messages are held.
You can use an e-mail client such as Mozilla or Microsoft Outlook for testing purposes. Simply set
the outgoing SMTP machine to be the CanIt-Domain-PRO relay (in our example, canit.example1.com
and send messages to people in your organization.
Alternatively, you can use a UNIX or Linux machine with its own DNS server. Create an MX record
for your domain pointing to the CanIt-Domain-PRO server and send messages. Remember, only the
test machine thinks that CanIt-Domain-PRO is your mail relay; the rest of the Internet still uses your
existing mail server.
C.6.2
Create a Test Subdomain
Another option is to create a test subdomain, such as test.example1.com. Configure your regular mail server to accept mail for that domain, and don’t forget to modify the CanIt-Domain-PRO
server’s access and mailertable files to relay mail for that domain. Then publish an MX record for
test.example1.com pointing to canit.example1.com. You can then send mail from anywhere in the Internet to someone at test.example1.com and it will be relayed through the CanIt-Domain-PRO server.
Existing mail to your proper domain, however, will still travel via your old mail server.
C.7
Route Real Mail
Once CanIt-Domain-PRO has passed the initial tests, it’s time to route real e-mail through it. The
safest way to do this is to add an additional MX record for your domains. This record should have the
highest priority, and point to the CanIt-Domain-PRO server.
For example, let’s suppose your existing MX records look like this:
example1.com.
example1.com.
1d IN MX 10 mail.example1.com.
1d IN MX 15 m2.example1.com.
Simply add another MX record like this:
example1.com.
1d IN MX 5 canit.example1.com.
and propagate the DNS changes. Mail for your domain will now be routed through the CanIt-DomainPRO machine. In an emergency, if you need to take the CanIt-Domain-PRO machine offline, simply
kill Sendmail on the CanIt-Domain-PRO server. Relays attempting to deliver mail to your domain
will first try the CanIt-Domain-PRO server and immediately get a “Connection refused” error. They
will fall back very quickly to the remaining MX records, and mail will flow as usual.
C.8. OUTGOING MAIL
Note:
313
This test setup is not a viable topology for stopping spam. Because CanIt-Domain-PRO sends
temporary-failure codes for suspect mail, if your real mail server has an MX record, the sender will
simply relay the spam directly to it. For production use, all of your public records should either:
• Be running CanIt-Domain-PRO, or
• Relay to a machine running CanIt-Domain-PRO.
The actual internal mail server should be hidden (no MX record) and ideally firewalled off, so only
the CanIt-Domain-PRO relay can connect to it.
C.8
Outgoing Mail
If you want to pass outgoing mail through CanIt-Domain-PRO, configure your mail server to use
the CanIt-Domain-PRO server as a “SmartHost”. This is a host to which all non-local mail will be
sent. The details of SmartHost configuration differ among mail servers; consult your mail server
documentation for details.
314
Appendix D
CanIt-Domain-PRO Architecture
D.1
Introduction
CanIt-Domain-PRO is based on the Sendmail Milter API, described at http://www.milter.
org/developers/design. Milter is a scalable API for doing site-wide filtering of e-mail.
Figure D.1 shows how CanIt-Domain-PRO interfaces with Milter.
315
316
APPENDIX D. CANIT-DOMAIN-PRO ARCHITECTURE
Sendmail
Sendmail
Sendmail
Milter Interface
mimedefang
Unix−domain Socket
mimedefang−multiplexor
Pipes
mimedefang.pl
mimedefang.pl
mimedefang.pl
Figure D.1: CanIt-Domain-PRO Architecture
D.2
CanIt-Domain-PRO Architecture
In Figure D.1, we show multiple sendmail processes communicating with a single mimedefang
process. The mimedefang executable uses the Milter reference library, and is therefore multithreaded. The mimedefang process is shown in cyan because it is the only multi-threaded process in CanIt-Domain-PRO; all others are single-threaded. The interface between mimedefang and
sendmail may be a local (UNIX-domain) socket or a TCP socket.
mimedefang takes care of accepting e-mail headers and bodies from sendmail and writing them
to a temporary spool directory (typically, /var/spool/MIMEDefang). It then sends short commands to mimedefang-multiplexor.
mimedefang-multiplexor listens on a UNIX-domain socket and manages a pool of Perl processes which do the actual filtering. The multiplexor has the following responsibilities:
1. It listens for requests from mimedefang and assigns them to one of the Perl processes.
2. It starts more Perl processes (up to a configured limit) if load increases.
D.3. STARTING AND STOPPING CANIT-DOMAIN-PRO
317
3. During times of low load, it kills off Perl processes (down to a configured limit.)
4. It kills Perl processes which have processed a configured number of messages. This is done to
avoid potential memory leaks.
5. It kills Perl processes which take too long to scan a message or which stop responding to requests.
mimedefang.pl is the actual Perl filtering program. It listens for requests (from the multiplexor)
on its standard input, and writes results to its standard output. The commands and results exchanged
are quite short; any modifications to the e-mail message are done in the spool directory.
Because the multiplexor manages several Perl processes, the Perl filters do not have to be thread-safe.
In addition, the “pool-of-preforked-processes” architecture scales very well on SMP systems, and is
efficient, robust and reliable.
D.3
Starting and Stopping CanIt-Domain-PRO
CanIt-Domain-PRO is started by a script called /usr/share/canit/scripts/canit-system.
This script handles the starting and stopping of multiple CanIt-Domain-PRO services and is invoked
with a single argument; possible arguments are:
start Starts all relevant CanIt-Domain-PRO services on this host.
stop Stops all CanIt-Domain-PRO services running on this host.
stop-most Stops all CanIt-Domain-PRO services running on this host except for those services
that are required for database access.
restart Equivalent to stop followed by start.
stop-gracefully Stops all CanIt-Domain-PRO services running on this host. Unlike stop, this
argument waits for any processes performing critical work to exit on their own. It is thus safer
stop, but may take a lot longer.
stop-most-gracefully Similar to stop-most but waits for processes performing critical
work to exit on their own.
restart-gracefully Similar to restart but waits for processes performing critical work to
exit on their own.
check Starts all CanIt-Domain-PRO services that should be running on this host but are not, and
stops all services that are running on this host but should not be.
status Prints the status of CanIt-Domain-PRO services on this host. Exits with an exit code of 0
if all services that should be running are running, and all services that should be stopped are
stopped. Exits with a code of 1 otherwise.
318
D.4
Static Configuration Files
Most
CanIt-Domain-PRO
services
read
a
configuration
file
called
/etc/mail/canit/canit.conf for static configuration settings, before reading the remainder of the configuration from the database. This file contains local configuration items that
differ from factory defaults. The meanings of some of the configuration settings are described below.
Boolean variables can take the values yes or no, while other variables are integers or strings.
D.4.1
Database Settings
The following settings exist in the [database] section of the configuration file.
db host (string) should be set to the host name or IP address of the database server. If the database
server is on this host, this setting should be blank.
db name (string) should be set to the name of the CanIt-Domain-PRO database, typically spam.
db super (string) should be set to the name of the PostgreSQL super-user, typically postgres.
db user (string) should be set to the name of the PostgreSQL user for normal database access, typically spam.
db super passwd (string) should be set to the name of the PostgreSQL super-user’s password, if you
are using MD5 authentication.
db passwd (string) should be set to the name of the PostgreSQL normal user’s password, if you are
using MD5 authentication.
db port (integer) may be set to the TCP port number of the PostgreSQL server. You should set this
only if your PostgreSQL server listens on a non-standard port.
db connect timeout (integer) should be set to the timeout for connecting to the PostgreSQL database
in seconds. The default timeout is 20 seconds.
D.4.2
Cron Settings
The [cron] section contains three settings that control the nightly cron job. They are:
compress dump (boolean) If set to yes, then the nightly database dump will be compressed with
gzip.
keep dumps (integer) Specifies how many nightly dumps to keep. CanIt-Domain-PRO will rotate
the nightly dumps, keeping at least keep dumps days’ worth of dumps.
bayes data expiry days (integer) Specifies when Bayes databases should be deleted. If a Bayes
database has not been modified in this many days, it is considered stale and removed. The
default value is 365. Any value less than 90 is ignored and silently changed to 90.
D.4. STATIC CONFIGURATION FILES
319
seen address expiry days (integer) Specifies how long CanIt-Domain-PRO should track valid addresses that have been seen. The default value is 61; acceptable values range from 30 to 365.
parallel tasks (integer) One of the tasks the cron job does is to check which domains validate
recipients. Normally, this is done by a single process, which can be slow. You can set
parallel tasks to a number from 1 to 500 to specify how many parallel tasks to run to
do recipient verification. Note that you should not set this value to more than about half of
mx maximum in the [mimedefang] section (described below).
autotask billing push days If set to a comma-separated list of numbers, the Autotask billing update
cron job is only run on the corresponding days of the month. For example, setting this variable
to 1,15 would run the Autotask update on the 1st and 15th of the month.
connectwise billing push days If set to a comma-separated list of numbers, the ConnectWise billing
update cron job is only run on the corresponding days of the month. For example, setting this
variable to 1,15 would run the ConnectWise update on the 1st and 15th of the month.
D.4.3
MIMEDefang Settings
These settings exist in the [mimedefang] section of the configuration file. As most do not
need to be modified from factory defaults, you may not have a [mimedefang] section in your
/etc/mail/canit/canit.conf file, so do not be alarmed if it does not exist.
mx user (string) should be set to the user ID of the mimedefang processors. This should nearly
always be a dedicated user called defang.
mx relay check (boolean) enables filtering of relay IP addresses during SMTP connection. CanItDomain-PRO does not filter at connect-time, so this should be set to no.
mx sender check (boolean) enables checking of the sender address in the SMTP “MAIL FROM:”
command. CanIt-Domain-PRO performs sender checks at “RCPT TO:” time in order to take
recipient streams into account, so this should always be set to no.
mx recipient check (boolean) enables checking of the recipient address in the SMTP “RCPT TO:”
command. CanIt-Domain-PRO requires this check, so it must be set to yes.
mx log (boolean) enables logging. This should always be set to yes.
mx requests (integer) specifies how many requests each Perl filter will handle before being killed.
The filters are killed after this number of requests to eliminate any possibility of problems due
to memory leaks. The default is 200, which should be reasonable for most installations.
mx max recipok per domain (integer) specifies how many concurrent “RCPT TO:” checks are allowed per domain. The default is zero, which means no limit. You can set this to some number
smaller than mx maximum to reduce the likelihood of one domain affecting others adversely.
For example, if one domain has a slow or dead verification server, limiting this setting protects
other domains from denial of service caused by all scanners doing RCPT TO: checks for the
slow domain.
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mx minimum (integer) specifies the minimum number of Perl filters to keep running, even if the
system is idle.
mx maximum (integer) specifies the maximum number of Perl filters to run concurrently, no matter
how busy the system is.
Note that each Perl filter requires a database connection. The default installation of PostgreSQL
permits only 32 simultaneous database connections. If you need more than this, you should
increase the number of PostgreSQL back-ends with the “-N” and “-B” postmaster options
when you start the database. Please see the postmaster(1) and pg ctl(1) man pages for details.
mx idle (integer) specifies how long in seconds a Perl process should be idle before it is killed off. After a period of heavy load, idle processes eventually get killed off until there are mx minimum
Perl filters running.
mx busy (integer) specifies how long in seconds a Perl filter is allowed to process a message. If
the filter takes longer than this, it assumed to have hung up and is killed, and the message is
tempfailed.
mx cmd timeout (integer) specifies how long in seconds to wait for commands and results to be
transferred between mimedefang and mimedefang-multiplexor.
mx slave delay (integer) specifies how long to wait after starting each Perl filter. If the system is
idle, but fewer than the minimum number of filters are running, a new filter is started each
mx slave delay seconds.
mx min slave delay (integer) specifies that the multiplexor must not start slaves more quickly than
the specified delay, no matter what. Even if the system is busy, a new filter will not be started
more often than every mx min slave delay seconds. Setting this to 1 or 2 seconds may help
your machine withstand a sudden surge in e-mail; it helps smooth out sudden load increases.
However, it may cause delays as some mail is tempfailed.
mx max rss (integer) specifies the maximum resident-set size in kB of each Perl filter process. On
systems which support this limit, a Perl filter which exceeds this limit is killed. If set to zero,
the limit is ignored.
mx max as (integer) specifies the maximum virtual address space in kB of each Perl filter process.
On systems which support this limit, a Perl filter which exceeds this limit is killed. If set to zero,
the limit is ignored.
mx stats (boolean) specifies that the multiplexor should log statistical information in
/var/log/mimedefang/stats.
mx flush stats (boolean)
specifies
that
the
multiplexor
/var/log/mimedefang/stats each time it writes a line to the file.
should
flush
mx stats syslog (boolean) specifies that the multiplexor should log statistical information using syslog.
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mx socket (string) specifies the full path to the UNIX-domain socket used for communication
between mimedefang and mimedefang-multiplexor. For CanIt-Domain-PRO, this
should not be changed.
group accessible files (boolean) specifies whether or not the files and sockets created by MIMEDefang should be group-accessible. If you set this to yes, then MIMEDefang-created files are
group-readable and sockets are group-readable and group-writable.
log times to syslog (boolean) specifies whether or not to log filter times using syslog. If you set this
to yes, then CanIt-Domain-PRO will log lines similar to this in your mail log:
gBNEeeI9004056: Filter time is 231ms
syslog ident (string) specifies the identifier to include in syslog messages. It defaults to CanIt. You
should not change this; it will be used by future versions of CanIt-Domain-PRO for log analysis.
mx embed perl (boolean) specifies whether or not the multiplexor should use an embedded Perl
interpreter. Normally, when a Perl slave is needed, the multiplexor forks and the child execs
a Perl program. If you set this to yes, then the multiplexor uses an embedded Perl interpreter
that reads the Perl filters only once. When a new slave is needed, only a fork is done. The
overhead of the exec and the Perl interpreter initialization is avoided.
On some systems, it is not possible to embed a Perl interpreter. If you set this flag to yes on
such a system, a warning is logged to syslog and CanIt-Domain-PRO continues as if the flag
were no.
On some systems, it is possible to embed a Perl interpreter, but not to safely destroy it and create
another interpreter in the same process. On such systems, a warning is logged if you force a
filter reread. This will not affect the operation of CanIt-Domain-PRO, but if you edit the actual
Perl filter file, you will need to do a (more expensive) mimedefang-ctrl restart rather
than the cheaper mimedefang-ctrl reread.
D.4.4
Filter Settings
A few filter settings are stored in the configuration file rather than in the PostgreSQL database. They
reside in the [filter] section. These filtering settings are used in the event that the database is not
available.
admin address The e-mail address of the CanIt-Domain-PRO administrator.
database down action This setting can take one of three values:
• tempfail (the default). CanIt-Domain-PRO will tempfail mail if the PostgreSQL
database server is non-responsive.
• accept. If the database is down, mail will be delivered un-scanned with a warning added
in the X-Spam-Score: header.
• minimalfilter. CanIt-Domain-PRO will run with bare SpamAssassin rules in tagonly mode.
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database down virus action If database down action is set to ’accept’, this parameter controls how viruses are handled while the database is down. It must be set to one of reject, discard
or accept.
database down tag score If database down action is set to ’minimalfilter’, this parameter
controls the threshold at which incoming mail is tagged. The default value is 5.
database down reject score If database down action is set to ’minimalfilter’, this parameter
controls the threshold at which incoming mail is auto-rejected. The default value is 20.
D.4.5
Ticker Settings
The [ticker] section contains settings related to the ticker tasks run by the CanIt daemon. If you
wish to change the settings, be sure to change them on the ticker machine (or on all machines for ease
of maintenance.)
pending notifications parallel senders (integer). Normally, CanIt-Domain-PRO uses one process
to send pending notifications. This can take a long time; you can run multiple parallel processes to speed it up. This parameter can range from 1 to 100, though the maximum value we
recommend is about 30.
pending notifications throttle db queries (boolean, default false.) If this is set to true, then the
pending notification tasks sleep if a particularly expensive query to gather pending messages
take a long time. This sleep time is dynamically adjusted (see the next setting.) Note that this
setting and the next are ignored unless pending notifications parallel senders is greater than
one.
pending notifications throttle target duration (integer, default 4). This specifies the target duration in seconds of the pending-notification SQL query. If the query takes longer, then the sleep
time between notifications is increased. If it takes less time, then the sleep time is decreased.
remail held messages parallel senders (integer). Normally, CanIt-Domain-PRO uses a single process to release and remail held messages. You can specify up to 50 parallel processes if you
find that releasing held messages is taking too long. Note that the number you specify here is
an upper limit. If there are not many held messages requiring release, CanIt-Domain-PRO may
use fewer processes than this limit.
index archived mail parallel indexers (integer). This setting applies only if you have installed the
CanIt Archiver add-on. Normally, CanIt-Domain-PRO uses only a single background process
to index mail that has been archived. If this process is unable to keep up with your archiving
volume, you may specify up to 50 parallel indexing processes.
D.4.6
Storage Manager Settings
The [storagemanager] section contains the following settings related to Storage Manager:
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pidfile (string) A file used by the Storage Manager server to write its process ID and
to lock against concurrent Storage Managers.
The default value is /var/run/
canit-storage-manager.pid.
rootdir (string) The root directory under which data are stored. The default value is /var/lib/
canit-storage-manager.
archive root (string) The root directory under which mail is archived (used only if you have installed
the Archiver component.) THe default is /var/lib/canit/mail-archive.
listen backlog (integer) The value of the “backlog” parameter for the Storage Manager daemon’s
listen() system call. The value can range from 5 to 128; the default is 16.
user (string) The UNIX user as which the Storage Manager server should run. The default value is
defang.
client retry delay (integer) specifies the delay in reconnecting to a dead storage manager node. If
a CanIt-Domain-PRO cluster node fails to connect to a storage manager node, it will not retry
the connection for client retry delay seconds. This can help prevent a dead storage
manager node from bogging down the clients in blocked connect calls.
client connect timeout (integer) specifies the timeout in seconds for a connection attempt to a Storage Manager node. The default is 5 seconds.
client operation timeout (integer) specifies the timeout in seconds for a read or write operation to a
Storage Manager node once connection has been established. The default is 20 seconds.
order (string) specifies the order in which to try Storage Manager nodes. The default is “auto”,
in which case CanIt-Domain-PRO periodically measures the latency to each Storage Manager
node and accesses them in order of increasing latency (fastest to slowest). If you want to specify
a particular order, set the value to a space-separated list of fully-qualified host names. The hosts
will be tried in the order given. If you do not specify all the hosts, then any remaining hosts are
tried after the ones specified by the order parameter.
check latency interval (integer) specifies how often in seconds to measure Storage Manager latency
if the order is set to “auto”. This value can range from 300 to 86400 seconds, with the default
being 3600 seconds or one hour.
disk bandwidth percent for pack prune (integer) specifies how much of the available disk bandwidth the Storage Manager should use when pruning very old files and packing old files
into CDB containers. By default, the nightly maintenance task that prunes and packs old
files will use all available disk bandwidth. If you find this increases the load too much, set
disk bandwidth percent for pack prune to an integer from 25 to 100. A setting of 50, for
example, will make the Storage Manager sleep after each disk operation for as long as the disk
operation took, meaning a 50-50 split between disk operations and sleeps.
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D.4.7
Maintenance Notification
If CanIt-Domain-PRO is unable to connect to the database, the Web interface normally prints an
error message. If you create a file called /etc/mail/canit/db-error.html that contains
HTML text, the contents of that file are sent to the browser instead, in a page entitled “System Down
for Maintenance”. Thus, if you know you’ll be bringing the system down, create an appropriate
db-error.html file and stop PostgreSQL (or firewall it off from the Web server.) Be sure to delete
db-error.html once the maintenance has been completed.
Rather than stopping PostgreSQL, you can also create a file called /etc/mail/canit/IN\
_MAINTENANCE\_MODE. If this file and /etc/mail/canit/db-error.html are both readable, then CanIt-Domain-PRO puts the Web interface into maintenance mode.
D.5
Tuning CanIt-Domain-PRO
Tuning CanIt-Domain-PRO is a bit like tuning Sendmail: A black art. Nevertheless, we can offer
some guidelines which should help improve the performance of your CanIt-Domain-PRO installation.
D.5.1
Memory
Your CanIt-Domain-PRO server should have sufficient memory. As a rule of thumb, you should have
about 50MB of memory for each concurrent Perl filter. If you set the maximum number of Perl filters
to 16, for example, your machine should have at least 800MB of physical memory.
Your CanIt-Domain-PRO server should also have sufficient swap space that a sudden flood of e-mail
does not cause exhaustion of virtual memory. An additional 32MB of swap space for each Perl filter
is probably a good rule of thumb.
D.5.2
Disk
You should have fast, reliable disks on your CanIt-Domain-PRO server. In particular, the CanItDomain-PRO spool directory (/var/spool/MIMEDefang) is heavily used, and it may be worth
putting it on its own disk. Even better, put the spool directory on a RAM disk, assuming you have
sufficient memory. A RAM-based CanIt-Domain-PRO spool directory is a large win, especially on
systems like Solaris with relatively conservative file systems.
To calcluate the amount of RAM you’ll need for the spool, multiply the size of the largest message
you’ll accept by the maximum number of concurrent filters, and then multiply by 3 as a safety factor
for CanIt-Domain-PRO processing. For example, if you accept messages up to 3MB, and you’ll have
at most 8 Perl filters running, then your /var/spool/MIMEDefang space should be at least 72MB.
If you use a RAM disk for the spool directory, add this memory to the memory requirements in the
previous section.
D.6. DEALING WITH OVERLOAD
D.5.3
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Solaris-Specific tmpfs Note
Solaris is very conservative about committing writes to disk. On a busy Solaris server, consider it
mandatory to put /var/spool/MIMEDefang on a RAM-based tmpfs file system. The performance improvement will be dramatic.
D.5.4
CPU
Spam-scanning is quite CPU-intensive, but in modern computers, the CPU is unlikely to be the bottleneck. If the CPU does prove to be a bottleneck, you should consider a faster machine, or even a
multiprocessor machine.
D.5.5
Sendmail
Tuning Sendmail is quite complex; for a review of some of the issues involved, we recommend “Sendmail Performance Tuning” by Nick Christenson, Addison-Wesley, ISBN 0-321-11570-8.
D.6
Dealing with Overload
Normally, the resources which first become overloaded in a mail server are disk or network bandwidth.
However, a server with CanIt-Domain-PRO installed is more likely to run out of CPU power or memory, simply because content-scanning is relatively expensive. If your CanIt-Domain-PRO machine
becomes overloaded to the point that very little mail is flowing and the machine is struggling, here are
tuning tips to help you recover.
D.6.1
Tune CanIt-Domain-PRO and Sendmail
In addition to the tuning tips in Section D.5, two parameters are particularly helpful in letting the CanItDomain-PRO server deal with overload: In /etc/mail/canit/canit.conf, set mx maximum
in the [mimedefang] section to a fairly low number, around 5 or 6. On most hardware, this should
limit the impact of scanning on CPU and memory. It will allow the CanIt-Domain-PRO machine to
process incoming mail smoothly until the overload conditions abate.
In conjunction with mx maximum, it is very useful to set Sendmail’s ConnectionRateThrottle
option. If you set this to 3, for example, Sendmail will accept at most 3 SMTP connections per second.
Again, this lets your machine process mail smoothly until overload conditions abate.
So if your server becomes overloaded, follow these recovery steps:
• Set mx maximum to 5, and ConnectionRateThrottle to 3.
(If you use
M4 to generate the sendmail configuration file, the M4 parameter is called
confCONNECTION RATE THROTTLE.)
• Watch the load carefully. If your machine appears to have idle time and free memory on its
hands, cautiously increase the parameters until throughput seems to be maximized.
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D.6.2
Network Architecture
A good way to deal with temporary overload conditions is to have a secondary MX machine that
simply relays mail without doing any scanning. It will queue messages that the primary machine
cannot handle, and then deliver them serially to the primary machine, smoothing out the load. The
disadvantage of this scheme is that some relay-IP tests do not work as effectively, and the secondary
MX machine may have to generate bounce messages.
If your CanIt-Domain-PRO machine is overloaded a lot of the time, we suggest setting up a second equal-weighted MX machine with CanIt-Domain-PRO installed. The two CanIt-Domain-PRO
machines can share the same PostgreSQL database, since database access is rarely the bottleneck.
Having two equal-weighted MX records will spread the load over both machines.
Appendix E
CanIt-Domain-PRO HOWTOS
E.1
Restoring a Database from a Dump
The CanIt-Domain-PRO cron job makes a text dump of the entire database every night; the database
is dumped into /var/spool/Canit-Spam-DB-Backup/SPAM-DATABASE-BACKUP. You
should back this file up to ensure the integrity of your spam database.
If, for some reason, you need to restore the database from the text file, follow this procedure. Note that
you may need to supply the full path to the PostgreSQL utilities like pg dump, psql, createuser,
etc.
All of these examples assume that the PostgreSQL superuser is named postgres. This is likely to
be true on Linux and Solaris, but some platforms use pgsql instead (this is the setting in FreeBSD’s
port of PostgreSQL.)
1. Stop CanIt-Domain-PRO, the ticker, Sendmail and the CanIt-Domain-PRO Web interface.
2. Dump your existing database, just to be safe. Be sure to do this in a directory with sufficient
space:
$ pg dump -U postgres spam > spam-dump-file.txt
3. Drop the database:
$ dropdb -U postgres spam
4. Create an empty database:
$ createdb -U postgres -E sql-ascii -l C -T template0 spam
5. Restore the database contents from the nightly dump file:
$ psql -U postgres -d spam < SPAM-DATABASE-BACKUP
6. Analyze the database to update statistics for the query optimizer:
$ psql -U postgres -d spam -c ’ANALYZE VERBOSE’
Do not omit the ANALYZE step or your database will be very slow.
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328
APPENDIX E. CANIT-DOMAIN-PRO HOWTOS
7. Restart CanIt-Domain-PRO, Sendmail and the CanIt-Domain-PRO Web interface.
Note:
The steps above apply if you restore the database onto the same machine it was originally on. If, for
some reason, you had to completely rebuild the machine, follow the steps in Section E.5.
E.2
Firewall Settings
Many people run CanIt-Domain-PRO behind a packet-filtering firewall. If you do, be sure to permit
access to the following ports. “Inbound” and “Outbound” are from the perspective of the CanItDomain-PRO machine. For example, if we say that outbound TCP port 80 must be open, we mean
CanIt-Domain-PRO must be able to initiate TCP connections to an external machine with a destination
of port 80. And when we say inbound TCP port 25 must be open, we mean CanIt-Domain-PRO must
be able to accept TCP connections from another machine destined to port 25.
E.2.1
Firewall Rules: External Hosts
CanIt-Domain-PRO needs the following ports open for communication with external machines on the
Internet:
• Inbound and outbound TCP port 25 for SMTP.
• Inbound TCP port 22 for SSH access.
• Outbound TCP and UDP port 53 for DNS lookups
• Outbound TCP port 80 and port 443 for software updates, RPTN downloads and ClamAV signature downloads.
• Outbound TCP port 873 for rsync access to additional ClamAV signatures.
• Outbound UDP port 6568 to report IP address reputation data back to Roaring Penguin Software.
• Possibly inbound and outbound UDP port 123 if you are using NTP to synchronize the clock.
E.2.2
Firewall Rules: Internal Hosts
CanIt-Domain-PRO needs the following ports open for communication with internal machines in your
organization. CanIt-Domain-PRO always needs port 25 open; the other three items are required only
if you use the corresponding User Lookup (Chapter 7.)
• Outbound TCP port 389 for LDAP lookups and/or 636 for LDAPS lookups.
• Outbound TCP port 110 for POP3 lookups and/or 995 for POP3S lookups.
• Outbound TCP port 143 for IMAP lookups and/or 993 for IMAPS lookups.
• Outbound TCP port 25 for verification servers and e-mail delivery.
E.3. RUNNING SOMETHING AFTER THE NIGHTLY CRON JOB COMPLETES
E.2.3
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Firewall Rules: Intra-Cluster Hosts
If you have a cluster of CanIt-Domain-PRO machines, the following ports are used between cluster
members and should be open:
• TCP port 5432 (typically) for PostgreSQL database connections.
• TCP port 6568 (typically) for Storage Manager connections.
• TCP port 22 for SSH connections.
Note that the PostgreSQL and Storage Manager ports should be firewalled off from external hosts and
hosts that are not members of the CanIt-Domain-PRO cluster.
E.3
Running Something after the Nightly Cron Job Completes
The script /usr/share/canit/scripts/canit.cron runs once a night to perform various
maintenance tasks. (Note that on some systems, canit.cron might be located in a different directory.)
If a file called post-cron-hook is present in the same directory as canit.cron and is executable, then it will be run as root after all other cron tasks have been completed. You can use this
script for whatever purposes you like. For example, you might use it to rsync the nightly database
dump to another machine for backup purposes.
See Section 19.7 for more information on which data to back up.
The following example uses rsync to move the nightly dump, the Bayes data, and a tarball of
/etc/mail/ to a new location:
#!/bin/sh
rsync /var/spool/Canit-Spam-DB-Backups/SPAM-DATABASE-BACKUP \
/backups/SPAM-DATABASE-BACKUP
rsync -av /var/spool/MD-Bayes/DB/ /backups/var/spool/MD-Bayes/DB/
tar jcvf /tmp/etc-mail.tar.bz2.tmp /etc/mail/ \
&& mv -f /tmp/etc-mail.tar.bz2.tmp /backups/etc-mail.tar.bz2
Note:
In this exmaple /backups/ is a directory on which some external storage is mounted. Replace
/backups/ with -essh <user@address>:/location/ for rsync to move the files to a
remote server instead.
Note:
The /var/spool/MD-Bayes/ directory and its descendants are sensitive to file ownership and
permissions, so preserve them if possible or be sure to reset them after a restore if not. See Section 19.2
for more information.
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E.4
Hooks
A hook is a script that you supply and that CanIt-Domain-PRO runs when certain events occur. To
create a hook, simply create a script in the directory /usr/share/canit/hooks. The script must
have the same name as the hook name (described below) and must be executable and readable.
The following hooks are defined:
• post-cron — runs as root
This hook is run just before the nightly cron job finishes.
• failed-over — runs as root
This hook is run on the backup database server just as failover is initiated. Note that the hook
runs before failover has actually taken place.
• remove-node-from-cluster — runs as root
This hook is called when a node is about to be removed from the cluster by the canit-removenode-from-cluster script.
• reinsert-node-into-cluster — runs as root
If mail queues do not drain in time when attempting to remove a node from the cluster, CanIt
reinserts the node into the cluster and calls this hook.
• shut-down-node-post-removal — runs as root
This hook is called just before a node that has been removed from the cluster is shut down.
• pre-start — runs as root
This hook is called when /etc/init.d/canit-system start is invoked. If it exits with a non-zero
status, then CanIt startup is aborted!
• gen-sendmail-maps-failed — runs as root
This hook is called if the script that generates new Sendmail map files from the Domain Routing
table fails.
• gen-sendmail-maps-succeeded — runs as root
This hook is called if the script that generates new Sendmail map files from the Domain Routing
table succeeds. It is called after the new mailertable and access files have been generated.
E.5
Migrating CanIt-Domain-PRO to a Different Machine
The following instructions will guide you through migrating to a different server. It is necessary to stop
processing mail during the migration. The amount of time this will take depends mostly on the size
of your database. Review the time-stamps on START-BACKUP-TIME and STOP-BACKUP-TIME
in /var/spool/Canit-Spam-DB-Backup for an idea of this time-frame. Assume restoring the
database will take 4/3 as long as dumping it does.
By default mail will be tempfailed during the migration. Most sending mail servers will not give
warning Delivery Status Notifications back to the sender unless attempts to deliver to you have failed
for 4 hours.
E.5. MIGRATING CANIT-DOMAIN-PRO TO A DIFFERENT MACHINE
331
If you determine that your migration down-time will be too long, there are two options: (1) Allow mail
to flow through un-scanned; (2) implement databaseless filtering. Please contact Roaring Penguin
Technical Support for details on these options.
You may wish to upgrade your CanIt-Domain-PRO installation at the same time.
E.5.1
CanIt-Domain-PRO Clusters
If you have a cluster of CanIt-Domain-PRO servers there may be additional considerations. If you are
migrating the database server it will be necessary to stop all CanIt-Domain-PRO servers during the
migration since the database will not be available during the dump and restore.
It is safe to install the latest version of CanIt-Domain-PRO on the new machine as long as all members
of the cluster are also upgraded. In a cluster all servers must run the same version of CanIt-DomainPRO.
The migration procedure includes the necessary steps for clusters. However, you must consult the
Clustering Guide after migrating to ensure that all machines in the cluster remain properly configured.
E.5.2
Storage Manager
If you are running Storage Manager there may be additional considerations. If you are running only
one Storage Manager node and it is on the server being migrated then your Storage Manager data must
be moved during the migration as well. However, in most cases it takes too long to copy this data from
one machine to another.
Therefore, in this case, the recommended procedure is to keep your old CanIt-Domain-PRO server
running Storage Manager in read-only mode for some time after the migration is complete. You may
either: (a) leave the old server running until its Storage Manager data expires (typically 30 days); or
(b) begin copying the Storage Manager to the new machine once migration is complete. The latter
option should take much less time (a few days) but requires extra steps.
If you run multiple Storage Manager nodes and have configured your cluster to store at least two
copies of all data, then migration will not be a problem since the other nodes will carry all of the data.
The migration procedure includes the necessary steps for Storage Manager (both options listed above).
E.5.3
Migration Procedure
1. Install CanIt-Domain-PRO on the new server. You may install the latest version.
Note:
Please ensure that CanIt-Domain-PRO is fully installed on the new server. In particular, PostgreSQL roles must be initialized with the canit-prepare-system command, even though
you will restore from another database shortly. It is not necessary to run this command on a fresh
CanIt-Domain-PRO Appliance/ISO install, although it is safe to do so.
2. Stop CanIt-Domain-PRO on the new server, the existing server, and all existing cluster members:
# /etc/init.d/sendmail stop
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# /etc/init.d/canit-system stop-gracefully
(If your version of CanIt-Domain-PRO is old, you might need to use stop instead of
stop-gracefully.)
Disable the CanIt-Domain-PRO web interface for non-admin users by visiting Administration : Disable/Enable.
Note:
If your CanIt-Domain-PRO version is older, this function may not be present. If this is the case,
or to be extra careful, stop Apache entirely (e.g. /etc/init.d/apache2 stop).
These services must be stopped to ensure that no process attempts to access the database while
the dump or restore is occurring. To completely ensure safety, you may also set PostgreSQL to
listen only on the loopback address:
Find postgresql.conf and set the listen addresses parameter to ’localhost’.
Be sure that only one such parameter exists in the file. Restart PostgreSQL for this to take effect.
Note:
After this step CanIt-Domain-PRO is no longer processing mail.
3. Dump the database to a file:
$ pg dump -U postgres spam > spam-dump-file.txt
Note:
This command may run for a long time without producing any output. This is normal.
4. Copy the file to the new server. This can be done with ssh:
# scp spam-dump-file.txt root@new machine:/root
5. Copy the entire directory tree rooted at /var/spool/MD-Bayes to the new machine, being
sure to preserve ownership and permissions. There are various ways to do this. However, in the
common case in which the old and new machine both have rsync and ssh installed:
# rsync --archive -essh /var/spool/MD-Bayes new machine:/var/spool
You may wish to add the --verbose and --progress flags if you have a lot of data to
copy.
6. If your domains were entered manually into /etc/mail/mailertable and
/etc/mail/access, you must transfer that information to the new server. If your
new server now has Setup : Domain Routing in its Web Interface you should enter the
domains there once the database is successfully restored.
You may wish to make a tarball of /etc/mail/ to keep as a reference on the new machine. This is handy if you later need to refer to files such as access, mailertable,
sendmail.mc, etc.
Note:
WARNING: Do not overwrite /etc/mail/ on the new server!
# tar zcvf old-etc-mail.tar.gz /etc/mail
# scp old-etc-mail.tar.gz root@new machine:/root
E.5. MIGRATING CANIT-DOMAIN-PRO TO A DIFFERENT MACHINE
333
7. On the new machine, restore the database from your file:
# dropdb -U postgres spam
# createuser -U postgres -S -D -R spam
(The createuser command may fail if the spam user already exists.)
# createdb -U postgres -E sql-ascii -l C -T template0 spam
# psql -U postgres spam < /root/spam-dump-file.txt
# psql -U postgres spam -c ’ANALYZE VERBOSE’
# canit-prepare-system
Note:
psql -U postgres spam < /root/spam-dump-file.txt will produce output.
However when it restores the largest table it may appear as though the process has frozen.
It is processing a very large table and may take a long time before further output is generated.
8. Log into the Web Interface on the new server and go to Administration : Enable/Disable and
disable CanIt-Domain-PRO if it is not already disabled. This prevents non-admin access to the
Web Interface for recent versions.
This is also a good time to ensure that all your domains are entered into Setup : Domain
Routing if your new server has this function.
9. Storage Manager migration 1: skip this step if you do not need to migrate your Storage Manager
data.
Configure the networking on the old server so that it will be accessible when the new server’s
final networking configuration is complete.
data.
Access the Web Interface for Storage Manager (see section 16.2.2) and update the networking
information. The old server must be set as a Read-Only Hostname. Update the new server’s
hostname in the Hostnames if it will be different when migration is complete.
11. Clear out all hosts from the cluster members table and system check tables:
# psql -U postgres spam -c ’DELETE FROM cluster members’
# psql -U postgres spam -c ’DELETE FROM cluster sanity check’
# psql -U postgres spam -c ’DELETE FROM cluster sanity check state’
12. Cluster considerations: skip this step if you do not have a cluster.
Review the Cluster Checklist in the Clustering Guide to ensure that all cluster members are
configured correctly in your new post-migration configuration.
For example, the scanners may need to have their database IP address updated.
Note:
Before proceeding, ensure all cluster members are running the same version.
13. Reconfigure the networking on the new server to its final configuration if necessary.
334
14. Restart CanIt-Domain-PRO on the new server and all cluster members:
# /etc/init.d/canit-system start
# /etc/init.d/sendmail start
Note:
Mail may now flow. Adjust any firewalls, networking equipment or MX records if necessary.
15. Click on Setup : Cluster Management and make sure the expected hosts are all present and
correctly configured. Adjust any settings as required.
You may need to re-run the commands from step 11 to clear the cluster members and system
check tables. After doing so, restart CanIt-Domain-PRO on the new database server before
restarting other cluster members.
data, or if you have chosen to allow the old server to remain operating until all data has expired
rather than copying it.
Begin copying the Storage Manager data from the old server to the new:
# rsync --archive --verbose --progress -essh \
/var/lib/canit-storage-manager root@newmachine:/var/lib/
Note:
This operation may take a very long time, perhaps many hours or even days. You may omit the
--verbose or --progress Rsync flags if you don’t want to monitor the Rsync progress.
Go to the Storage Manager Wizard in the Web interface and remove the old server from the
Read-Only Hostnames. You may now shut down the old server.
E.6
Cloning a CanIt-Domain-PRO Machine
If you clone a CanIt-Domain-PRO machine, either with disk-imaging software or a virtual environment’s cloning mechanism, do not bring up the cloned machine without first deleting the file
/etc/mail/canit/canit-cluster-member-id. Otherwise, the cluster management system will assume the cloned machine is still the original machine and will become confused.
Appendix F
Using CanIt-Domain-PRO with
memcached
F.1
Introduction
Memcached is a “distributed memory object caching system.” CanIt-Domain-PRO can use memcached to cache the results of Verification Server Lookups. In future, it might make more extensive
use of memcached to improve performance.
F.2
Using memcached
To use memcached with CanIt-Domain-PRO, you need to install memcached and then configure
CanIt-Domain-PRO to use it.
F.2.1
Installing memcached
On our Debian-based CanIt-Domain-PRO appliances, you can install memcached and its client libraries by running the following command as root:
# apt-get install memcached libcache-memcached-perl php5-memcache
On other platforms, you’ll have to use your system’s package manager to install memcache, the
Cache::Memcached Perl module, and the Memcache PHP extension.
F.2.2
Configuring memcached
Configuring memcached is beyond the scope of this manual. Consult the memcached documentation
for details on setting the various memcached configuration options.
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APPENDIX F. USING CANIT-DOMAIN-PRO WITH MEMCACHED
F.2.3
Single vs. Multiple Caches
On a CanIt-Domain-PRO cluster, memcached can be run in one of two basic ways:
1. A single cache. In this case, each cluster member communicates with the same memcached
daemon (or set of daemons.) There is one cache for the entire cluster.
2. Separate caches. In this case, each cluster member runs its own copy of memcached. Each
memcached daemon is used only by the node on which it is running.
Each mode has its advantages and disadvantages. A single cache allows more data to be cached and
makes cache hits more likely. However, if a cache node fails, then the entire cluster will be affected.
Timeouts when doing cache lookups could negatively affect performance.
If you use separate caches, then less data can be cached and cache misses become more common.
However, the failure of one node does not affect any other nodes in the cluster.
To avoid a single point of failure, therefore, we recommend using separate caches: Each CanItDomain-PRO cluster member should run its own instance of memcached.
F.2.4
Configuring CanIt-Domain-PRO to use memcached
Once you have installed memcached and configured it to run, edit the CanIt-Domain-PRO configuration file (typically /etc/mail/canit/canit.conf) and add a [cache] section. This section
should look something like this:
[cache]
use_cache = yes
driver = memcached
servers = 127.0.0.1:11211
single_cache = no
cache_valid_recipients = yes
cache_invalid_recipients = no
The lines have the following meanings:
• use cache = yes is required to enable caching. Otherwise, CanIt-Domain-PRO will not use
memcached.
• driver = memcached is required. In the future, other drivers may be supported, but for now,
only memcached is.
• servers = server list specifies the memcached servers. It should be a comma-separated list of
server descriptions. Each server description is a host name or IP address followed by a colon
and the TCP port number on which memcached is listening.
• single cache = no specifies that each CanIt-Domain-PRO cluster member runs (and uses) its
own independent copy of memcached. If the entire cluster uses the exact same set of memcached
servers, then set single cache to yes.
F.3. WHAT IS CACHED
337
• cache valid recipients = yes specifies that CanIt-Domain-PRO should cache valid recipient
results from verification servers. A setting of yes is recommended.
• cache invalid recipients = no specifies that CanIt-Domain-PRO should not cache invalid recipient results from verification servers. A setting of no is strongly recommended unless you
know with absolute certainty that the back-end verification server only ever rejects invalid recipients and never rejects valid recipients. Some back-end servers may reject valid recipients for
policy reasons and this could cause CanIt-Domain-PRO to incorrectly cache a valid recipients
as being invalid.
Once you have edited canit.conf, restart CanIt-Domain-PRO.
F.3
What is Cached
Currently, CanIt-Domain-PRO caches verification server results only. It caches a valid recipient for
24 hours, and an invalid one for one hour. This can reduce the number of times CanIt-Domain-PRO
needs to connect via SMTP to the verification server, and generally improves the recipient-checking
time by a factor of two or more.
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APPENDIX F. USING CANIT-DOMAIN-PRO WITH MEMCACHED
Appendix G
Using CanIt-Domain-PRO with
PgBouncer
G.1
Introduction
PgBouncer is a “Lightweight connection pooler for PostgreSQL” developed by Skype and available at
http://pgbouncer.projects.postgresql.org/.
PgBouncer is very effective at reducing database load in large CanIt-Domain-PRO installations by reducing the number of simultaneous PostgreSQL processes. CanIt-Domain-PRO works very well with
PgBouncer in “Transaction Pooling Mode”, which makes very effective reuse of existing PostgreSQL
processes.
G.2
Note:
Installation
We will only describe the installation and operation of PgBouncer with our Debian-based CanItDomain-PRO appliance build. Although it is possible to use PgBouncer on other systems, this is
not officially supported; you’ll have to install and configure PgBouncer yourself on those systems.
To install PgBouncer on a CanIt-Domain-PRO appliance, type:
# apt-get update
# apt-get install pgbouncer
G.3
Configuration
The PgBouncer configuration files are located in /etc/pgbouncer. The files are:
• userlist.txt: A list of PgBouncer users and how they map to PostgreSQL users.
• pgbouncer.ini: The main PgBouncer configuration file.
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APPENDIX G. USING CANIT-DOMAIN-PRO WITH PGBOUNCER
If you use PgBouncer, you should run one PgBouncer instance on each CanIt-Domain-PRO cluster
member.
G.3.1
Configuring userlist.txt
Configuring /etc/pgbouncer/userlist.txt is very easy. It should contain exactly the following content:
"spam" "spam"
"postgres" "postgres"
G.3.2
Configuring pgbouncer.ini
There is a sample pgbouncer.ini file installed in /usr/share/canit. You should copy it
into /etc/pgbouncer and then edit it.
pgbouncer.ini has several sections. They should be configured as follows:
• The [databases] section should point all databases at your database host. If your database
host is db.example.org, then there should be a single line in the [databases] section
that reads:
* = host=db.example.org
That line tells PgBouncer to contact db.example.org for all databases.
Note:
If you use a host name for the database host, that name must have an A record in the DNS
because pgbouncer does not use hostnames defined in /etc/hosts. If your database host
does not have a proper DNS entry, use an IP address rather than hostname in pgbouncer.ini.
• The [pgbouncer] section has a wide variety of settings. The defaults in the sample file are
probably fine; if you need to tweak them, see the pgbouncer man page.
The sample configuration file causes pgbouncer to listen for client connections on port 6432.
G.3.3
Configuring CanIt-Domain-PRO to use PgBouncer
Once PgBouncer has been installed and configured, you need to tell CanIt-Domain-PRO to use it. To
do this, edit /etc/mail/canit/canit.conf and change the following settings:
• In the [database] section, set:
db host=127.0.0.1
db port=6432
• Also in the [database] section, set:
use pgbouncer=1
This is important if you use failover; it tells the failover code to edit pgbouncer.ini rather
than canit.conf when changing the database server during failover.
G.3. CONFIGURATION
341
Once PgBouncer has been configured, run /etc/init.d/canit-system restart-gracefully
on all cluster nodes.
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APPENDIX G. USING CANIT-DOMAIN-PRO WITH PGBOUNCER
Appendix H
CanIt-Domain-PRO Logging
H.1
General Information
CanIt-Domain-PRO logs messages regarding its operation using syslog. By default, these are logged
using the mail syslog facility to keep them together with Sendmail’s logs. This is recommended,
but if for some reason you wish to change it, you can do so by modifying the syslog facility
configuration setting in the mimedefang section of /etc/mail/canit/canit.conf.
In general, a CanIt-Domain-PRO log entry will consist (after the standard syslog preamble of date,
host, process name, and process ID) of the word CanIt: followed by the 14 character Sendmail
queue ID (or the text NOQUEUE) followed by another colon. After this comes the message-specific
information for that log type.
Several types of log message are generated, at different log levels:
Debugging messages Debugging messages provide very verbose, detailed information regarding the
internal workings of CanIt-Domain-PRO. These are logged using syslog’s debug facility, and
are turned off by default in shipped versions of CanIt-Domain-PRO.
You will probably never need to enable debug logging, but if you need to do so, you must edit
the CanIt-Domain-PRO filter file (/etc/mail/canit/canit-domain-pro-filter)
and add the line:
CanIt::Logger::set debuglevel( CanIt::Logger::DEBUG ON() );
to the filter initialize() function, and restart the CanIt-Domain-PRO service.
When enabled, debug logging provides extra debugging information. After the general log
entry info mentioned above, a debug message consists of DEBUG:, the message itself, and then
in parentheses, the line, file, function, and caller information for each debug message.
Note:
Enabling debug logging is not recommended on a heavily loaded production server, as the extra
syslog traffic will slow things down, and greatly increase the disk space required for your logs.
Regular log messages Regular log messages provide information about the normal operation of
CanIt-Domain-PRO and are logged at the ’info’ level.
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344
APPENDIX H. CANIT-DOMAIN-PRO LOGGING
Event messages Event log messages provide information about the normal operation of CanItDomain-PRO in a format that is both human readable and machine parseable. These are logged
at the ’info’ level.
Warning messages Warning messages indicate that an undesirable, but non-fatal, condition has occurred. These are logged at the ’warning’ level.
Error messages Error messages indicate that a failure has occurred within CanIt-Domain-PRO and
should be attended to immediately. These are logged at the ’error’ level.
H.2
Event Log Format
Event messages are logged in a format designed to be both human-readable and machine-parseable.
This format consists of comma-separated key=value pairs, where the key consists of entirely lowercase alphabetic characters, and the value consists of arbitrary text appropriate for that key, with problematic characters such as newlines and commas replaced with a % followed by their two-digit hexadecimal value.
With the exception of what, which always appears first, and subject, which will appear last if
present, the key/value pairs cannot be assumed to occupy any specific position in the log line. Depending on where and why the message was logged, different keys will be present.
An example log message is:
Jan 01 13:10:31 oxygen mimedefang.pl[9813]: CanIt: j4CHAVtu009864:
what=accepted, nrcpts=1, relay=192.168.10.8, score=2.5,
[email protected], stream=user1,
tests=HTML MESSAGE, subject=Yes%2C this is an example
(We have wrapped the output for readability; in reality, the log message would appear on a single line.)
Here we see the standard date, time, hostname, process name, and process ID from syslog, the name
CanIt:, the sendmail queue ID for the message being processed, and a number of key-value pairs
separated by commas.
The keys that can appear in an “event” log line are:
what This field provides the first indication of what happened to the message. The ’reason’ and
’detail’ fields provide further information
Valid values for ’what’ are:
accepted Message was accepted and relayed through. The ’reason’ field may contain one
of: approved, sender-whitelisted, domain-whitelisted, host-whitelisted, unscanned-toobig,
skip-spam-scan, opt-out, or no reason at all if none of those cases apply.
rejected Message (or sender, or recipient) was rejected and the sending relay was given
a 5xx failure code. The ’reason’ field may contain one of: auto-reject, auto-rejectno-incident, blacklisted-recipient, domain-blacklisted, exe, ext, host-blacklisted, invalidrecipient, mime, rbl-blacklisted, sender-blacklisted, too-large, or virus.
tagged Message was tagged and relayed through. what=tagged log lines will not contain a
’reason’ field.
H.2. EVENT LOG FORMAT
345
discarded Message was discarded silently. The ’reason’ field can be auto-reject, auto-rejectno-incident, exe, ext, mime, virus.
pending Message was quarantined and held for human review.
greylisted Message was greylisted with a 4xx code. what=greylisted lines will not contain a
reason field.
reason This provides secondary information (the ”why” to the ”what” above) regarding the disposition of an incoming connection. Valid values are:
approved Message was manually approved from the quarantine interface.
auto-reject Message was rejected. An incident is available and is indicated by the value for the
incident key.
auto-reject-no-incident Message was automatically rejected due to spam score, and no incident was created.
blacklisted-recipient The specified recipient was blacklisted
domain-blacklisted The domain of the sender’s address was blacklisted in the specified stream.
domain-whitelisted The domain of the sender’s address was whitelisted in the specified
stream.
exe The message contained a file with an extension considered executable on Microsoft operating systems. detail will contain the extension name. Note that CanIt-Domain-PRO
no longer generates the exe reason, but older versions used to. New versions of CanItDomain-PRO only generate the ext reason.
ext The message contained a file with a blocked extension. detail will contain the extension
name.
host-blacklisted The relay host was blacklisted in the specified stream.
host-whitelisted The relay host was whitelisted in the specified stream.
invalid-recipient The specified recipient was not valid.
mime The message contained a file with a blocked MIME type. detail will contain the
actual MIME type found.
opt-out The stream containing this message is configured to opt out of spam scanning.
rbl-blacklisted The relay sending this message was blocked by an RBL entry.
sender-blacklisted The sender address was blacklistedin the specified stream.
sender-whitelisted The sender address was whitelistedin the specified stream.
skip-spam-scan The originating relay was in a Known Network marked with “Skip Spam
Scan”
too-large The message was rejected because it was over the configured maximum size for
messages received. The detail key will contain the actual size of the message.
unscanned-toobig The message was not scanned for spam because it was over the configured
maximum size for scanning and could not be reduced below that size. The detail key
will contain the actual size of the message.
346
virus The message contained a virus payload. The detail key will contain the name of the
virus found.
attach types This provides details about attachment types found in the message. It consists of a
semicolon-separate list of filename extensions. Any filenames found inside an archive file are
prefixed with >.
For example, if an email message contains a PNG image attachment and a ZIP file, and the ZIP
file contains a DLL file, CanIt-Domain-PRO may log something like this:
attach types=png;zip;>dll
detail This provides further detail if necessary (and available) from certain tests. For example, if
what=discard and reason=virus, the detail key will contain the name of the virus found.
city The name of the city in which the SMTP sending relay is located, if it could be determined.
country code The two-letter ISO-3166 country-code in which the SMTP sending relay is located, if
it could be determined.
incident The numeric ID of the incident, if available. An incident ID will be available only if an
incident is associated with this message, either because it was created, or because the message
matched an existing incident.
resolved by If an incident was present for this message, this field provides the username of the user
responsible for accepting or rejecting the message.
nrcpts The number of recipients for the given message. In general, rather than listing the individual
recipients (which, in some cases could number in the hundreds), we use this key to provide only
the number. The exception is when a particular single recipient is affected. In that case, we use
the recipient key to log the actual address.
recipient If an envelope recipient is rejected for some reason, the recipient address is logged with this
key.
relay The IP address of the sending relay. If parsing of Received: headers is enabled, this contains
the address retrieved from the headers. Otherwise, the actual connecting relay IP is logged.
score The score for the message, if scoring rules were applied.
sender The envelope sender of the message.
header from The From: header address of the message. This is only logged if it is different from the
sender key. It is also not logged if the message content is not yet available (for example, if a
nonexistent recipient is rejected.)
subject The subject line of the message, if available. This key always appears last in the log message.
stream The name of the stream being applied to the message at the time.
tests A semicolon-separated list of test names (both SpamAssassin and CanIt tests) that triggered for
the message.
H.2. EVENT LOG FORMAT
347
os The SMTP client’s operating system name as determined by passive OS fingerprinting. Typically
something like “Windows” or “Linux”.
osver The SMTP client’s operating system version as determined by passive OS fingerprinting.
linktype The SMTP client’s Internet link type as determined by passive OS fingerprinting.
realm The name of the realm in which the message was processed.
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Appendix I
SNMP Agents for CanIt-Domain-PRO
I.1
Introduction
SNMP (“Simple Network Management Protocol”) is a protocol for monitoring networks. An SNMP
monitoring station typically polls an SNMP Agent via UDP and receives data about the monitored
facility.
CanIt-Domain-PRO includes an SNMP agent that integrates with the Net-SNMP package. (For more
information on Net-SNMP, please see http://www.net-snmp.org/)
Note:
This chapter is not a tutorial on SNMP, nor will it tell you how to configure Net-SNMP; we assume
you’re familiar with both. Also, we support the SNMP agents only on our Debian-based appliance
and our Red Hat Enterprse Linux RPMs; on all other systems, the SNMP agents are supplied on an
as-is basis without support.
To use the SNMP agent, ensure that Net-SNMP is installed, and that snmpd is configured and set to
start on system boot.
Data returned by an SNMP agent is described in a Management Information Base or MIB. You can
download the CanIt-Domain-PRO MIB by logging in to the Web interface as the administrator, selecting Setup : Wizards and then clicking Download CanIt SNMP MIB File.
I.2
The SNMP Agent
The SNMP agent included with CanIt-Domain-PRO monitors:
1. Sendmail queue sizes and number of processes.
2. MIMEDefang busy/free scanners.
3. Failover status.
The agent provides information under the MIB tree .1.3.6.1.4.1.10055, which corresponds to
enterprises.roaringpenguin.
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350
I.2.1
APPENDIX I. SNMP AGENTS FOR CANIT-DOMAIN-PRO
Enabling the agent
To enable the SNMP monitoring agent, add this line to snmpd.conf:
pass_persist .1.3.6.1.4.1.10055 /usr/share/canit/scripts/canit-snmp-agent
Additionally, the cron job /usr/share/canit/scripts/canit-snmp-cron must be set
up to run once per minute. On CanIt-Domain-PRO appliances, edit the file /etc/cron.d/canitsnmp and uncomment the line.
On other platforms, create a cron script that runs
/usr/share/canit/scripts/canit-snmp-cron as root once per minute.
I.2.2
Configuring SNMPd
You may need to configure your SNMP daemon to allow connections from your external monitoring
services. The following instructions apply to the Appliance Build. For other operating systems,
consult the distributor’s documentation or support resources.
To configure the SNMP daemon to listen on your external network interface,
/etc/snmp/snmpd.conf. Find this line:
edit
#agentAddress udp:161,udp6:[::1]:161
and uncomment it by deleting the leading # sign.
To tell the SNMP daemon to allow readonly connections, edit /etc/snmp/snmpd.conf. Add a
line like this:
rocommunity
public
default
You may prefer a different COMMUNITY name than public. If so, simply change the public
parameter to something else. You can also restrict access to the SNMP daemon by using a network
and mask such as 10.0.0.0/16 in place of default in the above line.
Finally, restart the daemon and test with the following two commands:
/etc/init.d/snmpd restart
snmpwalk -v 1 -c public localhost .1.3.6.1.4.1.10055
Note:
If the snmpwalk command doesn’t give any output, wait a minute before trying again. The daemon
may take a moment to fully start up, or the cron job may not have run yet.
I.2.3
Agent Data
The Sendmail portion of the agent returns information about the number of entries in the main queue
and the submission queue. The meanings of the variables are as follows; “sendmail” is short for
.1.3.6.1.4.1.10055.100:
I.2. THE SNMP AGENT
351
• sendmail.1.1.1.1 — constant integer 1
• sendmail.1.1.2.1 — constant string “Main Queue”
• sendmail.1.1.3.1 — number of messages in Sendmail’s primary queue
• sendmail.1.1.2.2 — constant string “Submission Queue”
• sendmail.1.1.3.2 — number of messages in Sendmail’s submission queue
• sendmail.1.1.2.3 — constant string “Sendmail Process Count”
• sendmail.1.1.3.3 — number of sendmail processes running
The MIMEDefang portion of the agent returns information about the number of messages processed
in the last 10 seconds, 1 minute, 5 minutes and 10 minutes; the average scan time in milliseconds, and
the average number of busy scanners. The meanings of the variables are as follows; “mimedefang” is
short for .1.3.6.1.4.1.10055.1:
• mimedefang.1.1.1.1 — constant integer 1
• mimedefang.1.1.2.1 — constant string “Max slaves”
• mimedefang.1.1.2.2 — constant string “Busy slaves”
• mimedefang.1.1.2.3 — constant string “Free slaves”
• mimedefang.1.1.3.1 — maximum number of scanning processes configured
• mimedefang.1.1.3.2 — number of busy scanning processes
• mimedefang.1.1.3.3 — number of free scanning processes
• mimedefang.2.1.2.1 — constant string “10 Seconds”
• mimedefang.2.1.2.2 — constant string “1 Minute”
• mimedefang.2.1.2.3 — constant string “5 Minutes”
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APPENDIX I. SNMP AGENTS FOR CANIT-DOMAIN-PRO
• mimedefang.2.1.2.4 — constant string “10 Minutes”
• mimedefang.2.1.3.1 — number of messages scanned in the last 10 seconds
• mimedefang.2.1.3.2 — number of messages scanned in the last 1 minute
• mimedefang.2.1.3.3 — number of messages scanned in the last 5 minutes
• mimedefang.2.1.3.4 — number of messages scanned in the last 10 minutes
• mimedefang.2.1.4.1 — average scan time in milliseconds times 1000 (last 10 seconds)
• mimedefang.2.1.4.2 — average scan time in milliseconds times 1000 (last 1 minute)
• mimedefang.2.1.4.3 — average scan time in milliseconds times 1000 (last 5 minutes)
• mimedefang.2.1.4.4 — average scan time in milliseconds times 1000 (last 10 minutes)
• mimedefang.2.1.5.1 — average busy scanners times 1000 (last 10 seconds)
• mimedefang.2.1.5.2 — average busy scanners times 1000 (last 1 minute)
• mimedefang.2.1.5.3 — average busy scanners times 1000 (last 5 minutes)
• mimedefang.2.1.5.4 — average busy scanners times 1000 (last 10 minutes)
Note:
The average scan time and average busy scanners values are reporting an average, which is normally a
floating-point value internally. Since SNMP does not have a floating-point type, we multiply the raw
value by 1000 so that the information can be reported using a SNMP integer type with an acceptable
level of precision.
If you have configured PostgreSQL failover as described in the CanIt-Domain-PRO Clustering Guide,
you will also be able to retrieve information about the status of PostgreSQL failover. The meanings of
the variables are as follows; “failover” is short for .1.3.6.1.4.1.10055.2:
• failover.1 — the type of server; one of “master” or “backup”.
• failover.2 — if 1, then the failover system is OK. If 0, then there are problems that should be
investigated.
• failover.3 — a count of errors seen in the PostgreSQL log file. (Meaningful only on the “master”
server.)
• failover.4 — a count of WAL files waiting to be consumed on the backup server. Always reported as 0 on the master server.
• failover.5 — the count of WAL files in the pg xlog directory on the master server. Always
reported as 0 on the backup server.
• failover.6 — the time of last base backup as a UNIX timestamp (seconds since 1 January 1970
00:00:00 UTC.) Always reported as 0 on the master server.
• failover.7 — the time the last WAL file was shipped to the backup server as a UNIX timestamp.
Always reported as 0 on the master server.
Appendix J
Additional Scripts
CanIt-Domain-PRO ships with additional scripts that you may find useful. Please note that these
scripts are not officially supported by Roaring Penguin Software Inc.
J.1
reset-password.pl
The script /usr/share/canit/scripts/reset-password.pl lets you reset the administrator password if you forget it. To run the script, simply type:
# /usr/share/canit/scripts/reset-password.pl
and follow the prompts.
353
354
APPENDIX J. ADDITIONAL SCRIPTS
Appendix K
Bayes Database Back-Ends
Note:
K.1
PostgreSQL Bayes Data Storage
By default, versions of CanIt-Domain-PRO prior to 3.2.0 store Bayesian statistics in the PostgreSQL
database in a table called bayes. At a large site, Bayesian lookups can cause considerable database
traffic and substantial load on the database machine. CanIt-Domain-PRO has a mechanism to store
Bayesian statistics in CDB database files. These files are local to each scanner. Lookups are extremely
fast, and involve no database traffic and no load on the PostgreSQL database. Similarly, updates do
not involve the PostgreSQL database, which can greatly improve performance.
Note:
As of CanIt-Domain-PRO version 3.3.0, the PostgreSQL back-end is no longer supported, and cannot
be used.
K.2
Berkeley Database Bayes Storage
Versions 6.0.x and earlier of CanIt-Domain-PRO used BerkeleyDB to store Bayesian statistics. In
current versions, we now use CDB for the same data. CanIt-Domain-PRO can now read both BerkeleyDB and CDB Bayesian statistics files, but will only write CDB files. As such, no conversion step
is necessary – all Bayesian statistics will be migrated to CDB storage as new training is performed.
K.3
CDB Database Bayes Storage
CDB storage of Bayes data operates as follows:
• The master database files are stored on the machine running the ticker. Each stream has its own
database file under the directory /var/spool/MD-Bayes/DB.
355
356
APPENDIX K. BAYES DATABASE BACK-ENDS
• Bayes training is performed by the ticker. It updates the master CDB database files. If you are
running a cluster, the ticker then copies the updated database files to each scanning machine.
As a consequence of the way the CDB database files work, you must be aware of the following:
• You must have sufficient room under /var/spool/MD-Bayes/DB for all of your Bayes
data on the ticker machine and on each scanner.
• If you want to back up your Bayes data, you must back up /var/spool/MD-Bayes on the
ticker machine as well as backing up the nightly database dump.
• The ticker machine must be able to communicate via SSH to all scanning servers. SSH key
setup is performed automatically, so no additional configuration should be necessary beyond
the setup of a proper CanIt-Domain-PRO cluster (see Section K.4.)
K.4
Cluster Considerations
CDB files need to copy the files to all your scanning machines. On a new cluster, this will be taken
care of with update propagation (see below). However, if you are adding a new server to an existing
cluster, you will need to copy over your data. If you have rsync and ssh installed, the following
commands can be used to copy the data over. They should be run as defang on the ticker machine;
we assume $SCANNERS is a list of all your newly-added scanners.
for mach in $SCANNERS ; do
rsync -essh --archive --progress --verbose /var/spool/MD-Bayes/DB \
$mach:/var/spool/MD-Bayes
done
K.4.1
Propagating Updates
Because the ticker can only update CDB databases locally on the ticker machine, a mechanism is required to copy updated files to all scanning machines. In recent versions (post-6.0.3) of CanIt-DomainPRO, this is performed via the standard cluster communication process using an automaticallygenerated shared SSH key.
Previous versions used sync-berkeley-db and sync-berkeley-db-multi scripts to synchronize the data; these are no longer necessary or supported.
K.5
Switching back to PostgreSQL Bayes Storage
As of CanIt-Domain-PRO 3.3.0, it is not possible to switch back to the PostgreSQL storage module
for Bayes data.
Appendix L
System Check Tests
CanIt-Domain-PRO features an extensive self-test system that checks for common misconfigurations
and emails the administrator if problems are detected. You can see an overview of the self tests on the
Setup : System Check page.
The tests are as follows:
ApplianceDebianRepositories If this test fails, then your appliance has non-Roaring Penguin repositories in its sources list. We do not recommend this.
ApplianceDebianVersion If this test fails, then your CanIt-Domain-PRO appliance cannot determine
its Debian version. Contact Roaring Penguin support personnel for assistance.
ApplianceDiskSpace If this test fails, then at least one filesystem on the CanIt-Domain-PRO appliance has less than 10% free disk space.
BaseURLConfigured If this test fails, you have not configured the Base URL of the CanIt-DomainPRO installation. Run through the Basic Setup Wizard (under Setup : Wizards) to correct
this.
BayesDatabaseFormat If this test fails, the Bayes storage mechanism from an old CanIt-DomainPRO installation is incorrect. Contact Roaring Penguin support for help.
ClamAVCurrent If this test fails, your ClamAV signatures are out of date. Check the Clam logs to
see what might be causing the problem.
ClusterMain databaseHost If this test fails, no cluster member is designated as the main database
host. Contact Roaring Penguin support for help.
ClusterScannerHost If this test fails, no cluster member is configured as a scanner. Fix this under
Setup : Cluster Management.
ClusterStorageManagerHost If this test fails, the Storage Manager is misconfigued. Run though
the Storage Manager Wizard to correct the problem.
ClusterTickerHost If this test fails, no cluster member is configured as a ticker. Fix this under
Setup : Cluster Management.
357
358
APPENDIX L. SYSTEM CHECK TESTS
ClusterWebserverHost If this test fails, no cluster member is configured as a Web server. Fix this
under Setup : Cluster Management.
CopyToCluster If this test fails, it indicates a problem copying Bayes data from the ticker host to
another host in the cluster. Make sure all hosts can communicate with each other over SSH on
TCP port 22.
Cron If this test fails, then the nightly cron job has not run recently. You should immediately investigate and take corrective action.
DatabaseDump If this test fails, it indicates that the nightly database dump has failed. You should
immediately take corrective action; check the log file canit-cron.log in the directory
/var/spool/Canit-Spam-DB-Backup to see what went wrong.
DatabaseVacuum If this test fails, it indicates that the nightly database vacuum has failed. You
should immediately take corrective action; check the log file canit-cron.log in the directory /var/spool/Canit-Spam-DB-Backup to see what went wrong.
DebianAutoUpgrade (Appliance Only) If this test fails, it indicates that you have set the upgrade
type to Automatic, but have a version of PostgreSQL that is too old to safely support automatic
upgrades. Until you can upgrade PostgreSQL, you may silence the warning by going to Setup
: Wizards and running the Upgrade Configuration Wizard. Set the upgrade type to Manual.
DeprecatedFiles If this test fails, it indicates there are some obsolete files from an old CanIt-DomainPRO installation. Contact Roaring Penguin support for help.
DeleteOnCluster If this test fails, it indicates a problem deleting Bayes data on a host in the cluster.
Make sure all hosts can communicate with each other over SSH on TCP port 22.
FailoverWALCount If this test fails on the backup database server, then you have set up PostgreSQL
failover but the backup PostgreSQL server is not consuming WAL files correctly. If this test fails
on the master database server, then the PostgreSQL pg xlog directory is filling up with WAL
files. There is likely a problem shipping the WAL files to the backup server.
Hostname If this test fails, then your host is called localhost. You should give it a real host name.
HostnameNotLoopback If this test fails, then a host’s canonical name resolves to the loopback address (i.e, 127.0.0.1 or ::1). This usually indicates a bad entry in /etc/hosts on the affected
machine. You should ensure that /etc/hosts does not contain an entry for the host pointing
it at 127.0.0.1 or ::1. Only localhost should point to the loopback address.
LicenseValid If this test fails, your license key is invalid. Contact Roaring Penguin support for help.
MainDatabase If this test fails, there isn’t exactly one machine in the cluster marked as the main
database server. Contact Roaring Penguin support for help.
MaxFSMPages If this test fails, PostgreSQL’s max fsm pages parameter is too low. You should
take immediate corrective action: Edit the PostgreSQL postgresql.conf file to increase
max fsm pages and restart PostgreSQL.
359
Note:
You may need to increase your kernel’s max. shared memory limit. If PostgreSQL fails
to restart after updating max fsm pages, revert your change and restart. Correct the
kernel.shmmax issue, then retry.
OldMSAQueueFile If this test fails, there is an old queue file in the Sendmail submission queue.
Make sure that Sendmail is running and that a submission queue runner is active.
OldMTAQueueFile If this test fails, there is an old queue file in the Sendmail main queue. Make
sure that Sendmail is running and that a main queue runner is active.
PhishListDownload If this test fails, the phishing list download has failed. Check the reason in the
description field to diagnose why the download failed.
PhishingLinksDownload If this test fails, the phishing URL download has failed. Check the reason
in the description field to diagnose why the download failed.
PostgresEncoding If this test fails, the your spam database uses the wrong encoding. Contact Roaring Penguin support for help.
PostgresVersion If this test fails, your version of PostgreSQL is too old. Contact Roaring Penguin
support for help.
PostgresXXX If this test fails, the corresponding PostgreSQL configuration value is too low. Increase
it in postgresql.conf and restart PostgreSQL.
RecipientVerification:XXX If this test fails, then there is no mechanism to verify recipients for the
given domain. You should enable recipient verification by doing one of the following:
1. Set up a Verification Server (Section 5.4.)
2. Set up a User Lookup method that validates recipients (Section 7.2.)
3. Use the Valid Recipients Table (see the Users’ Guide.)
RPTNBayesDownload If this test fails, an RPTN download has failed. Check the reason in the
description field to diagnose why the download failed.
RPTNEnabled If this test fails, you have not enabled RPTN downloads. Run through the RPTN
Setup Wizard (under Setup : Wizards) to correct this.
RPTNGeoDownload If this test fails, the geolocation data download has failed. Check the reason in
the description field to diagnose why the download failed.
RPTNRulesDownload If this test fails, a ruleset download has failed. Check the reason in the description field to diagnose why the download failed.
RPTNSynchronization If this test fails, then at least one scanner has no RPTN data (or outdated
RPTN data). Make sure your RPTN downloads are succeeding and that all cluster members can
communicate via SSH over TCP port 22.
StorageManagerConfig If this test fails, you have enabled the Storage Manager, but have not configured any read/write Storage Manager nodes. Run through the Storage Manager Wizard to
correct the misconfiguration.
360
SupportValid If this test fails, your support term is about to expire or has expired. Contact Roaring
Penguin’s sales department to extend your support.
TickerTable If this test fails, no ticker tasks are running. Contact Roaring Penguin support for help.
TickerTaskXXX If this test fails, the corresponding ticker task has not run recently. Contact Roaring
Penguin support for help.
VirusScannerEnabled If this test fails, then no virus scanners are enabled. You should enable a virus
scanner in /etc/mail/canit/virus-scanners.pl.
WebserverDeprecatedFiles If this test fails, there are obsolete files in the CanIt-Domain-PRO web
directory. Contact Roaring Penguin support for help.
L.1
Disabling System Checks
Although we do not recommend disabling system checks, you can selectively disable checks by editing /etc/mail/canit/canit.conf and creating a [sanitychecker] section. Within that
section, add lines of the form testname=ignore to ignore specific tests.
For example, if you wish to ignore the ApplianceDiskSpace test, add these lines to
canit.conf:
[sanitychecker]
ApplianceDiskSpace=ignore
L.2
Anomaly Detection
CanIt-Domain-PRO can detect and report certain anomalies that occur during operation. In addition
to being reported to the overall CanIt-Domain-PRO administrators, anomalies are reported to realm
administrators. A given realm administrator can see all anomalies for his or her realm, subrealms, etc.
If any anomalies have occurred, you will see the following notice when you first log in to CanItDomain-PRO:
Figure L.1: Anomaly Notice
To see details, click on Administration and then Anomalies.
Each anomaly reported consists of the following parts:
• Realm – the realm in which the anomaly occurred.
• Family – the general class of the anomaly.
L.2. ANOMALY DETECTION
361
• Detail – more detail about the anomaly (for example, the server or domain involved, etc.)
• Message – a human-readable error message.
• Time Frame – the time frame over which the anomaly has occurred. This shows the first and
last time the anomaly was observed.
The meanings of the various families are:
• AccountInfo::LDAP – something went wrong with an LDAP lookup. The “Detail” field will
contain the name of the particular User Lookup that failed and the “Message” field will explain
what happened.
• DesynchronizedDNS – the domain’s name servers disagree about its MX records. You should
fix the name servers so that all of them report the same set of MX records.
• DKIM – a domain has DKIM signing set up, but there is a problem with the domain’s
domainkey DNS record.
• RecipientVerification – a domain does not correctly validate recipients. The “Detail” field will
contain the domain name. You should enable recipient verification with one of the following
methods:
1. Set up a Verification Server (Section 5.4.)
2. Set up a User Lookup method that validates recipients (Section 7.2.)
3. Use the Valid Recipients Table (see the Users’ Guide.)
• VerificationServer – something went wrong trying to contact a verification server. The “Detail”
field will contain the server list.
L.2.1
Disabling Recipient Verification Anomaly Testing
If you wish CanIt-Domain-PRO to permit a domain not to validate recipients, you can disable the
RecipientVerification anomaly test as follows:
• Under Setup : Verification Servers, create a Verification Server entry for the domain where
the server name is the literal text ignore.
Note:
Although it is possible to disable Recipient Verification testing for a domain, we do not recommend
this. Allowing wildcard recipients could result in a large amount of useless scanning and wasted CPU
time.
362
L.2.2
More Details about Anomalies
If you require additional details about an anomaly, click on the link in the Time Frame column. The
Anomaly Details screen will appear:
Figure L.2: Anomaly Details
The anomaly details page will contain one row for each time the anomaly was logged. The Queue ID
column contains the Sendmail queue ID (if any) associated with the message causing the anomaly; if
you have the Log Searching and Indexing component installed, then the Queue ID will be a link that
takes you directly to the mail logs associated with a given occurrence of the anomaly.
L.2.3
Suppressing Anomaly Notification Emails
Normally, CanIt-Domain-PRO sends out an email to realm administrators once a night if it notices
anomalies. If you wish to suppress these messages, go to Administration : Anomalies and set
“Should the system send anomaly notification emails to realm administrator(s)?” to No. This setting
is inherited by sub-realms, so if you want to turn off anomaly notifications for a realm but leave them
on for a subrealm, you need to switch into the subrealm and override the parent realm setting.
Appendix M
The CanIt-Domain-PRO License
READ THIS LICENSE CAREFULLY. IT SPECIFIES THE TERMS AND CONDITIONS UNDER
WHICH YOU CAN USE CANIT-DOMAIN-PRO
This license may be revised from time to time; any given release of CanIt-Domain-PRO is licensed
under the license version which accompanied that release.
CanIt-Domain-PRO is distributed in source code form, but it is not Free Software or Open-Source
Software. Some CanIt-Domain-PRO components are Free Software or Open-Source, and we detail
them below:
The following files may be redistributed according to the licenses listed here. An asterisk (*) in a file
name signifies a version number; the actual file will have a number in place of the asterisk.
File
src/Archive-Tar-*.tar
src/Config-Tiny-*.tar
src/DBD-Pg-*.tar
src/DBI-*.tar
src/Data-ResultSet-*.tar
src/Data-UUID-*.tar
src/Digest-MD5-*.tar
src/Digest-SHA1-*.tar
src/File-Spec-*.tar
src/File-Temp-*.tar
src/HTML-Parser-*.tar
src/HTML-Tagset-*.tar
src/IO-Zlib-*.tar
src/IO-stringy-*.tar
src/Log-Syslog-Abstract-*.tar
src/MIME-Base64-*.tar
src/MIME-tools-*.tar
src/Mail-SPF-Query-*.tar
src/Mail-SpamAssassin-*.tar
src/MailTools-*.tar
License
Perl License
Perl License
Perl License
Perl License
Perl License
Perl License
Perl License
Perl License
Perl License
Perl License
Perl License
Perl License
Perl License
Perl License
Perl License
Perl License
Perl License
Perl License
Apache License, Version 2.0
Perl License
363
364
APPENDIX M. THE CANIT-DOMAIN-PRO LICENSE
File
src/Module-Pluggable-Tiny-*.tar
src/Net-CIDR-Lite-*.tar
src/Net-DNS-*.tar
src/Net-IP-*.tar
src/Time-HiRes-*.tar
src/TimeDate-*.tar
src/URI-*.tar
src/YAML-Syck-*.tar
src/clamav-*.tar
src/p0f-*.tar
src/libwww-perl-*.tar
src/mimedefang-*.tar
License
Perl License
Perl License
Perl License
Perl License
Perl License
Perl License
Perl License
Perl License
GPLv2
GPLv2
Perl License
GPLv2
ALL REMAINING FILES IN THIS ARCHIVE (referred to as ”CanIt-Domain-PRO”) ARE DISTRIBUTED UNDER THE TERMS OF THE CANIT LICENSE, WHICH FOLLOWS:
THE CANIT LICENSE
1. CanIt-Domain-PRO is the property of Roaring Penguin Software Inc. (”Roaring Penguin”).
This license gives you the right to use CanIt-Domain-PRO, but does not transfer ownership of
the intellectual property to you.
2. CanIt-Domain-PRO is licensed with a limit on the number of allowable protected domains or
mailboxes. This limit is called ”the Usage Limit”.
CanIt-Domain-PRO usage may be purchased on a yearly basis, or you may purchase a perpetual
license.
3. You may use CanIt-Domain-PRO up to the Usage Limit you have purchased. If you have
purchased yearly usage, you may continue to use CanIt-Domain-PRO until your purchased
usage time expires, unless you purchase additional time. If you have purchased a perpetual
license, you may continue to use CanIt-Domain-PRO indefinitely, providing you do not violate
this license.
If you have purchased yearly usage, you may exceed your purchased limit by up to 10% until
the yearly renewal date, at which time you must purchase a sufficient limit for the increased
number of domains or mailboxes.
If you have purchased a perpetual license, or wish to increase your usage more than 10% above
your paid-up limit, you must purchase the additional usage within 60 days of the increase.
4. You may examine the CanIt-Domain-PRO source code for education purposes and to conduct
security audits. You may hire third-parties to audit the code providing you first obtain permission from Roaring Penguin. Such permission will generally be granted providing the third-party
signs a non-disclosure agreement with Roaring Penguin.
5. You may modify the CanIt-Domain-PRO source code for your own internal use, subject to the
restrictions in Paragraph 9 below. However, if you do so, you agree that Roaring Penguin is
365
released from any obligation to provide technical support for the modified software. If you
wish your modifications to be incorporated into the mainstream CanIt-Domain-PRO release,
you agree to transfer ownership of your changes to Roaring Penguin.
6. You may make backups of CanIt-Domain-PRO as required for the prudent operation of your
enterprise.
7. You may not redistribute CanIt-Domain-PRO in source or object form, nor may you redistribute
modified copies of CanIt-Domain-PRO or products derived from CanIt-Domain-PRO.
8. If you violate this license, your right to use CanIt-Domain-PRO terminates immediately, and
you agree to remove CanIt-Domain-PRO from all of your servers.
9. Restrictions on modification:
(a) Notwithstanding Paragraph 5, you may not make changes to CanIt-Domain-PRO or your
software environment which would allow CanIt-Domain-PRO to run without a valid License Key as issued by Roaring Penguin. You also agree not to set back the time on your
server to artificially extend the validity of a License Key, or do anything else which would
artificially extend the validity of a License Key.
(b) You may modify the Web-based interface only providing you adhere to the following
restrictions:
(c) At the bottom of every CanIt-Domain-PRO web page, the following text shall appear, in a
size, color and font which are clearly legible:
Powered by CanIt-Domain-PRO (Version x.y.z) from Roaring Penguin Software Inc.
where x.y.z is the product version.
In addition, “CanIt-Domain-PRO” shall
be a clearly-marked hypertext link to http://www.roaringpenguin.com/
powered-by-canit.php
(d) You may not include elements on the CanIt-Domain-PRO Web interface that require plugins (such as, but not limited to, Macromedia Flash, RealPlayer, etc.) to function.
(e) You may not include Java applets on the CanIt-Domain-PRO Web interface.
(f) If you include JavaScript on the Web interface, you shall ensure that the interface functions
substantially unimpaired in a browser with JavaScript disabled.
(g) You shall not include browser-specific elements on the Web interface. You shall ensure
that the Web interface functions substantially unimpaired on the latest versions of the
following browsers:
•
•
•
•
Internet Explorer for Windows
Mozilla for Windows
Mozilla for Linux
Konqueror for Linux
(h) You may not include banner ads on the CanIt-Domain-PRO Web interface.
10. Restrictions on reselling services:
Unless you purchased CanIt-Domain-PRO as a service provider on the ISP rate plan, you may
not use CanIt-Domain-PRO to provide spam-scanning services to third parties. You may use
366
APPENDIX M. THE CANIT-DOMAIN-PRO LICENSE
CanIt-Domain-PRO only for your employees and contractors accounts on your own corporate
servers.
11. Disclaimer of Warranty (Virus-Scanning)
NOTE: ALTHOUGH CANIT-DOMAIN-PRO IS DISTRIBUTED WITH CLAM ANTIVIRUS,
WE DO NOT MAKE ANY REPRESENTATIONS AS TO ITS EFFECTIVENESS AT STOPPING VIRUSES. ROARING PENGUIN HEREBY DISCLAIMS ALL WARRANTY ON
THE ANTI-VIRUS CODE INCLUDED WITH CANIT-DOMAIN-PRO, OR WHICH INTERFACES TO CANIT-DOMAIN-PRO. WE ARE NOT RESPONSIBLE FOR ANY VIRUSES
THAT MIGHT EVADE A VIRUS-SCANNER INTEGRATED WITH CANIT-DOMAIN-PRO.
12. Disclaimer of Warranty (Time-Critical Mass Mailings)
CANIT-DOMAIN-PRO IS NOT DESIGNED FOR TIME-CRITICAL EMERGENCY MASS
MAILINGS. AN EMERGENCY MASS-MAILING MAY OVERLOAD CANIT-DOMAINPRO AND CAUSE DELAYS. ROARING PENGUIN HEREBY DISCLAIMS ALL WARRANTY ON THE ABILITY OF CANIT-DOMAIN-PRO TO DELIVER MASS MAILINGS IN
A TIMELY FASHION. IF YOU REQUIRE EMERGENCY MASS-MAILINGS YOU MUST
CONFIGURE THEM TO BYPASS THE CANIT-DOMAIN-PRO FILTER.
M.1
THE CANIT DATA LICENSE
Roaring Penguin makes available certain data that are used by CanIt. This license covers the RPTN
Bayes data and the Roaring Penguin RBLs. The data are owned by Roaring Penguin and their use is
licensed under the following terms:
1. You may update the RPTN data once per day per Roaring Penguin download username. Roaring
Penguin reserves the right to cut off downloads if more than one download per day per username
is attempted.
2. You may use the RPTN data only in conjunction with your properly-licensed CanIt installation.
3. You may not redistribute the RPTN data.
4. If your support term expires, you lose the right to use RPTN data for any purpose whatsoever.
5. You may make use of the Roaring Penguin RBLs from within CanIt. You may not query them
with any other software.
6. You may use the Roaring Penguin RBLs only in conjunction with your properly-licensed CanIt
installation.
7. You may not redistribute the Roaring Penguin RBL data.
8. If your support term expires, you lose the right to use the Roaring Penguin RBLs.
Index
access rights, see permissions
account-info, 149
active streams, 123
address mapping, 83
scenarios, 85
wildcards, 84
addresses, locked, 177
alias, 50
anomaly, 360
architecture, 316
attachment, 179
authentication, external, 137
backscatter, 132
backups, 217
base realm, 40
basic setup wizard, 56
Bayes Database, 355
Berkeley, 355
CDB, Cluster Considerations, 356
PostgreSQL, 355
Bayes journal, 154
Bayesian filtering, 153
voting
unauthenticated, 153
best practices, 214
branding, 79
canit.conf, 318
classes
stream, 157
cloning, 334
configuration file, 318
creating a group, 122
creating realms, 40
cron job, 106, 329
cron settings, 318
customization of theme, 79
data license, 366
database settings, 318
database, moving, 330
debugging logs, 343
default stream, 85
deleting a group, 122
deleting a stream, 125
deleting realms, 41
delivery status notification, blocking, 132
direct queue injection, 74
disabling features, 74
discarded message, 38
disclaimer, 125
disk imaging, 334
DNS blacklists, 110
domain configuration wizard, 219
domain mapping, 81
AsIs, 82
ChopDomain, 82
ChopUser, 82
Database, 82
Program, 82
domain, locked address, 177
download, RPTN, 154
downloading logs, 207
dump, restoring from, 327
event log, 344
expire, 106
non-spam, 106
spam, 106
external authentication, 137
false positive, 19
features, 74
direct queue injection, 74
disabling, 74
enabling, 74
367
368
INDEX
filter settings, 321
filtering outbound mail, 125
final stream, 167
firewall, 328
firewall rules
RPTN, 155
flow of mail, 28
forwarding logs, 208
geolocation data, 155
global settings, 105
grantability, permission, 163
greylisting, 23, 211
group, 122
creation, 122
deletion, 122
editing, 122
group permissions, 157
hooks, 330
HTTPS, 81
inheritance, 165
joe-job, 132
known networks, 65
license, 363
data, 366
locked address domain, 177
locked addresses, 177
logging, 343
events, 344
logs, downloading, 207
logs, forwarding, 208
logs, searching, 201
macros, office, 132
mail flow, 28
mapping, 50
maximum size, 105
memcached, 335
memory, 324
message
status, 36
message size, maximum, 105
milter, 23
MIMEDefang, 23
mimedefang settings, 319
moving database, 330
MX, secondary, 129
office macros, 132
opt-in, 107
outbound mail, filtering, 125
ownership and permissions, file, 215
periodic reports, 171
permission grantability, 163
permissions, 157
granting, 159
group, 157
stream, 157, 159
permissions and ownership, file, 215
phishing, 131
phishing URL, 132
phishing URLs, 112
plus hack, 108
post-cron-hook, 329
privileges
user, 117
root, 117
write, 117
program user lookup, 146
provisioning, 134
proxying
URL, 183
RAM, 324
rate-limiting, 69
real-time blacklist, 110
realm, 24, 39
base, 40
creating, 40
definition, 47
deleting, 41
mappings, 41
realm mappings, 41
receive-only addresses, 214
Received: header, 130
relay host, 24
remailing, 38
INDEX
369
report, RPTN, 154
reports, periodic, 171
restoring database, 327
rewrite, 149
Roaring Penguin Training Network, see RPTN
RPTN, 154
firewall rules, 155
RPTN download, 154
RPTN report, 154
RPTN setup wizard, 56
rule
copying, 128
prioritization, 28
ruleset update, 155
searching logs, 201
secondary MX, 37, 129
security, 215
network, 216
PHP, 216
PostgreSQL, 216
ssh, 216
Sender Policy Framework, see SPF
Sender Rewriting Scheme, see SRS
Sendmail plus hack, 108
server, verification, 57
settings, cron, 318
settings, database, 318
settings, filter, 321
settings, mimedefang, 319
settings, storage manager, 322
settings, ticker, 322
simple GUI, 165
simple interface, 108
Simple Mail Transfer Protocol, see SMTP
SMTP, 24
SMTP AUTH, 69
SMTP authentication, 107
SMTP Server Testing, 187
SNMP, 349
special streams, 167
SPF, 24
SRS, 24, 109
storage manager, 193
storage manager settings, 322
stream, 24, 47
active, 123
default, 51, 85
definition, 47
deleting, 125
final, 167
granting access to, 119
inheritance, 165
mapping, 50
special, 167
stream classes, 157
stream permissions, 157, 159
streaming, 32
methods, 33
AsIs, 33
ChopDomain, 33
ChopUser, 33
Database, 33
Program, 33
User Lookup, 33
syslog, 343
system check, 75
tempfail, 25
templates, 76
temporary failure, see tempfail
Testing, SMTP Server, 187
theme customization, 79
ticker settings, 322
tuning, 324
unauthenticated voting, 153
updates, rules, 155
URL Proxying, 183
URLs, phishing, 112
user
adding, 117
deleting, 119
editing, 118
user lookup, program, 146
user lookup, rewrite, 149
user privileges, 117
users, 116
verification server, 57
non-standard port, 59
virus, 106
370
INDEX
voting
unauthenticated, 153
welcome screen, 54
wizard, 56
basic setup, 56
RPTN setup, 56

CanIt-Domain-PRO Administration Guide

Transcription

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