Bayes Poisoning? Spam with negative BAYES Scores

[Nathan Johanson]

Hello,

A recent thread made brief reference to "bayes poisoning". We're
currently using SpamAssassin 2.60 and will upgrade to version 2.61
shortly, but we have seen an increasing amount of spam slipping through
the filters with negative BAYES scores. Very annoying:

X-tcpnetworks-MailScanner: Found to be clean
X-tcpnetworks-MailScanner-SpamCheck: not spam, SpamAssassin
(score=-3.361,
 required 4, BAYES_00 -4.90, HTML_IMAGE_ONLY_06 1.44,
 HTML_MESSAGE 0.10)

Is anyone else seeing this sort of thing? Any recommendations for
combating it? I noted the links to BigEvil custom rules (posted
earlier), but I'm starting to wonder if Bayes usefulness is starting to
dwindle. Is there some way to prevent this poisoning?


help too.

Nathan