I have recently had issues with a specific spammer, who uses a different IP each time and within a few hours blasts my mail server with spam.  Grey listing does no good.  Unlike most spammers don't get through on the first try and give up, this guy just hammers it for hours.  The result is I usually get about 2 - 3 copies of each spam message.  They push the same BS.  RachaelRay, Oprah, Cigars, IPhone tracker, ect....  I have noticed that their return email and from email often has those keywords in there.  So I have setup a content filter on my email address that looks for a deletes those messages.  But this doesn't help the othe 200 email account running on my server.  What I need is the ability to content filter the entire Server and not just my email box.  What would be even better is to have a rule that reads the from email address during the SMTP connection and blacklist the IP immediately.  Maybe even allow me to fire a script on my server that will add that IP to my firewall.  Spammers are getting smarter, and we need better tools to fight the issue.