What is "spamassassin"

SpamAssassin is a computer program used for e-mail spam filtering. SpamAssassin uses a variety of spam-detection techniques, including DNS-based and fuzzy-checksum-based spam detection, Bayesian filtering, external programs, blacklists and online databases. It is released under the Apache License 2.0 and is now part of the Apache Foundation.

The program can be integrated with the mail server to automatically filter all mail for a site. It can also be run by individual users on their own mailbox and integrates with several mail programs. SpamAssassin is highly configurable; if used as a system-wide filter it can still be configured to support per-user preferences.

SpamAssassin was awarded the Linux New Media Award 2006 as the "Best Linux-based Anti-spam Solution".