bsfilter is a spam filter using Bayesian(statistical) algorithm.

- a filter which distinguishes spam and non-spam mail
- support mails written in English and Japanese language
- written in Ruby
- support 3 methods for access
-- traditional Unix-style filter. study and judge local files or pipe
-- IMAP. study and judge mails in an IMAP server. IMAP over SSL supported
-- POP proxy. run between POP server and MUA. POP over SSL supported
- distributed under GPL

WWW: http://en.sourceforge.jp/projects/bsfilter/