At our September 2002 meeting, Barb Dijker of Netrack
talked about her experience with anti-spam tools that work,
focusing on SpamAssassin. Barb covered using SpamAssassin
integrated with procmail and through the milter mechanism
in sendmail, settling on the procmail approach as the
less troublesome way to use the software.
There was a lively discussion of other approaches to
filtering spam, including using black hole lists and
spam checksum databases.
Barb's slides are available here