- SpamAssassin
- Open Source mail filter, written in Perl, to identify spam using a wide range of heuristic tests on mail headers and body text. Free software. Can be used as a standalone mail filter, or from procmail. Site includes download, news, FAQ, and documentation.
- SpamAssassin - Book by Alan Schwartz. Description, reviews, table of contents, and short preview texts.
- SpamAssassin Bugzilla - Bug-tracking system for the SpamAssassin mail filtering project.
- SpamAssassin Rules Emporium - A community-maintained collection of custom rules for SpamAssassin.
- SpamAssassin sa-update Channel - Update server hosted by OpenProject, including the recommended rules from the SpamAssassin Rules Emporium. Includes usage instructions.
- SpamAssassin Wiki - User contributed documentation, testimonials, tricks and tips for the mail filtering software.
- SpamAssassin: A Practical Guide to Integration and Configuration - Online edition of a book by Alistair McDonald. Includes chapter summaries, and the full text from two chapters.
- Wikipedia: SpamAssassin - Encyclopedia article about the mail filtering software, including history and details of the various techniques employed.
