Hello, I'm on the verge of a major upgrade of our mail server.
In addition to new versions of everything, I'd like to make some major improvements to our SPAM rejection. It seems the most effective thing in the lineup now, are the RBLs. Greylisting seems to have largely lost it's ability to block SPAM (I guess the spam bots now retry in accordance w/RFC). One idea that I've been considering is to eliminate mail that shows up for multiple (unrelated) users, on different domains, within a short amount of time. I've noticed (I'm sure this isn't original) that SPAM messages often show up for many users across different domains all at once. Has anyone else tried such an approach? Is there any postfix infrastructure I could adopt to implement such a strategy? Also, could anyone recommend any other SPAM rejection policies I should put in place? Thank You! johnea
