Not to thread jack or anything, but when I first moved our cluster to
Spam Assassin, I was disappointed at the amount of messages that would
get past Spam Assassin at even a low threshold of 2.
I Googled around and found a bunch of rulesets that once installed,
started tagging those hard to get messages.
Also, use the various RBLs in the scoring. e.g. add 50% of the threshold
score if its on spamcop and 25% for some of the other more aggressive
RBLs. We have a very high and correct hit rate as a result. Our users can
then add white lists for the handful of their contacts that get tagged as
spam since they are using spam friendly ISPs.
