SpamAssassin: A practical guide to integration and configuration. In depth guide to implementing antispam solutions using SpamAssassin

SpamAssassin: A practical guide to integration and configuration. In depth guide to implementing antispam solutions using SpamAssassin - Opis

As a busy administrator, you know Spam is a major distraction in todays network. The effects range from inappropriate content arriving in the mailboxes up to contact email addresses placed on a website being deluged with unsolicited mail, causing valid enquiries and sales leads to be lost and wasting employee time. The perception of the problem of spam is as big as the reality. In response to the growing problem of spam, a number of free and commercial applications and services have been developed to help network administrators and email users combat spam. Its up to you to choose and then get the most out of an antispam solution. Free to use, flexible, and effective, SpamAssassin has become the most popular open source antispam application. Its unique combination of power and flexibility make it the right choice. This book will now help you set up and optimize SpamAssassin for your network. Spis treści:
SpamAssassin
Table of Contents
SpamAssassin
Credits
About the Author
About the Reviewers
Introduction
What This Book Covers
What You Need for Using This Book
Conventions
Reader Feedback
Customer Support
Downloading the Example Code for the Book
Errata
Questions
1. Introducing Spam
Defining Spam
Definitions
The History of Spam
Spammers
The Costs of Spam
Costs to the Spammer
Costs to the Recipient
Spam and the Law
Summary
2. Spam and Anti-Spam Techniques
Spamming Techniques
Open Relay Exploitation
Collecting Email Addresses
Hiding Content
Statistical (...) więcej Filter Poisoning
Unique Email Generation
Trojanned Machines
Anti-Spam Techniques
Keyword Filters
Open Relay Blacklists (ORBLs)
ISP Complaints
Statistical Filters
Email Header Analysis
Non-Spam Content Tests
Whitelists
Email Content Databases
Sender Validation Systems
Sender Policy Framework (SPF)
Spam Filtering Services
Collect and Forward
Collect and Return
Send and Forward
Choosing an Anti-Spam Service Provider
ISP-Provided Services
Anti-Spam Tools
SpamAssassin
How SpamAssassin Works
Easy to Use
Techniques Used by SpamAssassin
Summary
3. Open Relays
Email Delivery
Open Relay Tests
Automated Open Relay Testers
Manual Open Relay Testing
MTA Configuration
Sendmail
Sendmail Versions 8.9 and Above
Sendmail Versions Below 8.9
Postfix
The mynetworks Configuration Directive
The relay_domains Configuration Directive
Exim
Exim Configuration Parameters
qmail
Summary
4. Protecting Email Addresses
Websites
Alternative Character Representations
JavaScript
Usenet
Trojan Software
Mailing Lists and Archives
Registration for Websites
Tracking Email Address Usage
Sendmail Plus Technique
Rogue Employees
Employees
Business Cards and Promotional Material
How Spammers Verify Email Addresses
Web Bugs
Summary
5. Detecting Spam
Content Tests
Header Tests
DNS-Based Blacklists
Statistical Tests
Message Recognition
URL Recognition
Examining Headers
Faked Headers
Reporting Spammers
Valid Bulk Email Delivery
Summary
6. Installing SpamAssassin
Building from Source
Prerequisites
Checking Current Configuration
Installing Perl
Installing CPAN
Testing for a C Compiler
Using CPAN
Installing by Hand
Resolving Build Failures
Packaged Distributions
RPM
Debian
Gentoo
Other Formats
Windows
Verifying the Installation
Upgrading
Uninstalling
Uninstalling from Source
Using CPANPLUS
Other Packages
Uninstalling on Windows
SpamAssassin Components
Executables
Perl Modules
Documentation
Summary
7. Configuration Files
Configuration Files
Standard Configuration
Site-Wide Configuration
User-Specific Configuration
Rule Files
Rules
Scores
Summary
8. Using SpamAssassin
SpamAssassin as a Daemon
Creating a User Account
SpamAssassin and Procmail
Testing for Procmail
Obtaining and Installing Procmail
Configuring Procmail
MTA Configuration
sendmail
Postfix
Exim
qmail
Configuring User Accounts
Site-Wide Procmail Usage
Integrating SpamAssassin into the MTA
Sendmail
Sendmail Milter Support
MIMEDefang
Postfix
Exim
qmail
Testing and Troubleshooting
Check the MTA
Further Diagnosis
Rejecting Spam
Summary
9. Bayesian Filtering
Scoring
Training
Confirming Operation
Filter Training
User Involvement
Local Users
Unlearning
Auto-learn Thresholds
Bayesian Database Files
Removing a Bayesian Database
Sharing a Bayesian Database
Disabling Bayesian Filtering
Summary
10. Look and Feel
Headers
Changing Headers
Creating Headers
Removing Headers
Reports
Enabling and Disabling Reports
Changing Reports
Subject Rewriting
Summary
11. Network Tests
RBLs
SURBLs
SpamAssassin 2.63
Vipuls Razor
Installing Razor
Configuring Razor
Configuring SpamAssassin
Testing Razor
Pyzor
Installing Pyzor
Configuring Pyzor
Configuring SpamAssassin
Testing Pyzor
Pyzor Headers
DCC
Installing DCC
Configuring SpamAssassin
Testing DCC
DCC Headers
Spamtraps
Choosing a Spamtrap Address
Baiting the Spamtrap
Configuring the Email Account
Summary
12. Rules
Writing Rules
Rules Performance
Meta Rules
Writing Positive Rules
Examples of Positive Rules
Rawbody Rules
Using a Corpus to Test Rules and Scoring
Corpus Development
The Public Corpus
Testing SpamAssassin on a Corpus
Examining Hit Frequencies
Using Other Rulesets
Summary
13. Improving Filtering
Whitelists and Blacklists
Manual Whitelisting and Blacklisting
Whitelisting Domains
The Auto-Whitelist
Resolving Incorrect Classifications
Examining Messages
Changing the Spam Threshold
Re-weighting Test Scores
Increasing the Score of Spam Emails
Coping with False Positives
Bayesian Unlearning and Relearning
Character Sets and Languages
Disallowing Languages
Disallowing Character Sets
Summary
14. Performance
Bottlenecks
Memory
CPUs
Disk I/O
Network I/O
Determining Bottlenecks
Performance Improvement Methodology
Using the SpamAssassin Daemon
Integrating SpamAssassin into the MTA
Omitting Messages
Large Messages
Disabling Tests
Running Network-Based Tests First
Razor, Pyzor, and DCC
Using Additional Machines
Faster File Locking
Using SQL
Requirements
MySQL
Configuration
Spamd with SQL
SQL for User Preferences
Adding New User Preferences
Displaying User Preferences
Altering User Preferences
Deleting User Preferences
Testing if SQL User Preferences Are Being Used
Preference Precedence
SQL for Bayesian Databases
Testing if the SQL Bayesian Database Is Being Used
The Auto-Whitelist Database
Testing if the SQL Auto-Whitelist Database Is Being Used
Summary
15. Housekeeping and Reporting
Separating Levels of Spam
Detecting When SpamAssassin Fails
Spam and Ham Reports
Spam Counter
Keeping Statistics Over a Period of Time
Determining SpamAssassin Processing Time
Summary
16. Building an Anti-Spam Gateway
Choosing a PC Platform
Choosing a Linux Distribution
Installing Linux
Configuring Postfix
Accepting Email for the Domain
Mail for the root User
Basic Spam Filtering with Postfix
Forwarding Email to the Original Email Server
Reloading Postfix
Testing Postfix
Installing Amavisd-new
Installation from Package
Installing Prerequisites
Installing from Source
Creating a User Account for Amavisd-new
Configuring Amavisd-new
Configuring Postfix to Run Amavisd-new
Configuring External Services
Firewall Configuration
Backups
Testing
Going Live
Summary
17. Email Clients
General Configuration Rules
Microsoft Outlook
Microsoft Outlook Express
Mozilla Thunderbird
Qualcomm Eudora
Summary
18. Choosing Other Spam Tools
Spam Policies
Evaluating Spam Filters
Configuring the Second Filter
Using a Single Machine
Using Separate Machines
Sendmail
Postfix
Exim
qmail
Other Techniques
Greylisting
SPF
Sender Validation
Summary
A. Glossary
Index mniej