I manage our mail server and we've been getting more spam lately than usual. I want to amp up the filtration we use, but wanted to know if anyone had any recommendations. What specifically I'm looking for is how strict should I make the filter? Messages are scored according to the rules and once a message reaches a certain score (defined by me) it is marked as spam and treated accordingly. The question is, where should I set that limit? It was at 5.7 until I just changed it to 4. Should I go lower? Is that too low? Thoughts? If you manage a mail server with Spamassassin, where do you have yours set?
For me I started at 6 until I tune it to 4, it seemed that 4 is quite optimal, no complaints of false positives and not much complaints of too much spam. Maybe you should enable RBL using zen.spamhaus.org and bl.spamcop.net as well.