Tracking and Fighting Spam: A Primer for Postmasters

Unauthorized email floods are one of the biggest headaches faced by system administrators of Internet-connected networks. There are some effective strategies for reducing its drain on your resources. Spammers are thieves. They can argue about this all they want. They're hijacking your system to deliver their unrequested, unwanted advertising. If you pay for your bandwidth consumption, then they're charging you for the privilege. If you don't, then they're charging against your ISP for the privilege, and you can be sure that's included in your monthly fee�one way or another. The allegedly "legitimate" spammers have a bit more of a case; they don't hide where their mail is coming from, and they at least pretend to offer a way off their lists. But I'm not talking about that sort. I'm talking about the run-of-the-mill spammers. The pedestrian make-money-fast/mortgage fraud/gambling/pornmeisters who forge everything they can in the header, those who dump email on unsuspecting third parties to deliver for them�thus stealing from even more people than do "legitimate" spammers. These are the people who've forced site administrators to shut down relay services on their machines to stem the flow, thereby defeating a useful design function of the Internet. What does all this mean to you? If you want to track down spammers and get them shut down, you have the moral right, even, perhaps, the duty to do so. OK, maybe it's just a desire to see a spammer get hammered. Whatever. It's all right; they're the villains here. So where do you start? With a few specific tools available on the Web and a bit of analysis of the header you'll be ready to fight back.