spamhammerd

If you're looking for a way to combat spammers, then look no further than spamhammerd! This simple perl script is designed to help you keep those pesky spammers at bay.

To give you a quick rundown on how it works, spammers tend to be pretty sloppy in their attempts to flood your mail server. But spamhammer is built to watch your logfile (currently only compatible with postfix), and dynamically creates an accessfile. This way, it can track connection attempts and increment a counter every time a client attempts to send to an unknown user.

Here's where it really shines though, once a threshold has been crossed, the ip gets blocked for a configurable length of time. It may sound too simple to be effective, but in our experience with a large mailfarm, this method is incredibly effective at blocking the worst spam offenders.

In fact, our block list on any given smtp server usually hovers around 5000 lines. To get started with spamhammer, simply write: check_client_access hash:/etc/postfix/generated/spammers. It's simple, it's effective, and it could be the solution you've been looking for to help keep your mail server spam-free.