I’ve got a mailserver running on this host now… It still needs some heavy tweaking. However, I thought I’d point out policyd, which is a really neat package. It integrates into smtpd_recipient_restrictions, and I currently have it providing greylisting and some spamtrap mailboxes (though I’m not sure they work). It does much more, too.

It seems that greylisting works well, too. I’ve had 192 people greylisted, which is basically every mail connection that hasn’t been bounced for having a non-FQDN HELO. (Which is a surprising amount.) Only three have made it through, all of them legitimate. (policyd makes it possible for users to opt-in or opt-out of greylisting, though I’m currently the only user…)

Not terribly relevant, but now that I’m using PowerDNS with a MySQL backend, I realized I could easily set up a little process on our firewall to go out and hit a URL here, which updates the record periodically with our home IP. Easy home-grown dynamic DNS!