The Apache SpamAssassin Project
The Powerful #1 Open-Source Spam Filter
This is the home page for the open-source Apache SpamAssassin Project. There are also numerous prepackaged versions for Windows, commercial versions, and specialized front-ends.
If you were sent here because you received an e-mail message which was modified by SpamAssassin, please read this page.
2010-03-19: SpamAssassin 3.3.1 has been released, a minor new release which adds some new rules. Visit the downloads page to pick it up, and for more info.
- Wide-spectrum: SpamAssassin uses a wide variety of local and network tests to identify spam signatures. This makes it harder for spammers to identify one aspect which they can craft their messages to work around.
- Free software: it is distributed under the same terms and conditions as other popular open-source software packages such as the Apache web server.
- Easy to extend: Anti-spam tests and configuration are stored in plain text, making it easy to configure and add new rules.
- Flexible: SpamAssassin encapsulates its logic in a well-designed, abstract API so it can be integrated anywhere in the email stream. The Mail::SpamAssassin classes can be used on a wide variety of email systems including procmail, sendmail, Postfix, qmail, and many others.
- Easy Configuration: SpamAssassin requires very little configuration; you do not need to continually update it with details of your mail accounts, mailing list memberships, etc. Once classified, site and user-specific policies can then be applied against spam. Policies can be applied on both mail servers and later using the user's own mail user-agent application.