A mailet for integration with
SpamAssasin contributed by Josh Parreco
Spam Filtering Techniques by David Mertz, Ph.D
IETF Anti-Spam Research Group (ASRG)
Bayesian Classification in Java
See also: MailetIdeas, such as
TMDA support
Implementing Spam Filtering Gateway with Apache James
See also, regarding email issues
http://www.sans.org/rr/catindex.php?cat_id=19
Notes on using SpamAssassin with James 2.2.0 / Windows XP see SpamAssassinWithWindows