Screaming Penguin - Source Does Matter

Recently I have been researching more aggressive anti-spam features for sendmail. Out of the box sendmail can do explicit domain blocking, check validity of domains and validity of sender email address syntax and use blacklists. Beyond out of the box content filtering and more is possible. I have not quite decided on an overall approach yet but SpamCon is a big help in terms of resources. For more info check the SpamCon site for now and I will report the results of my research here later.   SpamCon: server filters