[afnog] Anti-Spam software

[Alan Barrett]

On Wed, 28 Sep 2005, orimbo at arcc.or.ke wrote:
> Folks, any other open anti-spam solution outside there? I use
> SpamAssassin but the problem is it suspects "legitimate" mails. I run
> Sendmail on Linux 9.0.

The trick with spamassassin is to configure it for your situation.
Enable Bayesian filtering, and train the Bayesian filters with samples
of both good and bad mail.  Also adjust the scores for various things up
and down according to your situation.

Somewhere in the spamassassin distribution is a script that tries to
optimise the scores to your situation, using a genetic algorithm.
You feed it a large pile of good and bad messages, let the script
run for a long time, and the result is a set of scores that have
evolved to minimise the number of false positives or false negatives
in the input sample.  I have never run this script, but I believe that
the spamassassin developers use it to try to tune the scores before
releasing new versions of spamassassin.

Even if you do all that, you will still end up with false positives and
false negatives.

--apb (Alan Barrett)