Mail-SpamAssassin  3.4.1
About: SpamAssassin is a mail filter that uses a wide range of heuristic tests on mail headers and body text to identify "spam" (also known as unsolicited commercial email) incl. Bayesian (statistical) spam filter and several internet-based realtime blacklists.
  Fossies Dox: Mail-SpamAssassin-3.4.1.tar.gz  ("inofficial" and yet experimental doxygen-generated source code documentation)  

Mail-SpamAssassin Documentation