We are running Spamassassin here on our mail server. Then the legitimate mail gets forwarded to our exchange server. We have had alot of spam come through to users, and would like to put an end to this. I've read that the bayes filter is a great way. Right now messages marked as spam go into a exchange mailbox called spam-trap. I need better documentation and understanding of bayes. It seems as if the tool it uses requires the mail to be available locally, but mine is on the exchange server.
Any information wo uld be helpful