I've added some super-magic postfix spam fighting rules, mostly RBL checks, based mostly on these pages. Please email me at alan ayt ufies dawt org if you find mail is broken or not going through for any reason.
Other than that, you should just see less spam in your inboxs, and my bandwidth costs (*cough*points to donate button*cough*) should be less! Everyone wins but the spammers, which means that everyone wins!