OverviewDenySpam monitors a mail server log file and uses a firewall to temporarily block or redirect incoming packets from hosts that display spammer-like behavior.
The primary benefit of DenySpam over other anti-spam solutions is that it stops many spammers before they waste your bandwidth and server resources, and it doesn't require any maintenance or training in order to be effective. And if you'd rather fight back instead of just blocking spammers outright, DenySpam integrates nicely with the spamd SMTP tarpit, which provides endless amusement by wasting the time and resources of spammers trying to connect to your server.
DenySpam comes configured for use with Postfix and pf, but should be usable with most Unix mail servers and firewalls with a little bit of configuration tweaking.
See the FAQ for a detailed description of how DenySpam works.
