Wednesday, September 05, 2007

Anti-spam for qmail: spamdyke

I have long been a fan of qmail. Yes, I know that it is long in the tooth, and there are a great number of fans of postfix and so forth out there, but say what you will about qmail -- it's solid as a rock, and incredibly fast. I am a big fan of it.

A few years ago I became a fan of the "cookbook" found on, but it is, sadly, a bit out of date. Nevertheless, careful perusal of various mailing lists and so forth has allowed me to keep up to date with my qmail installs and things are running along smoothly.

Recently, I found another weapon to use in the ongoing battle with spam: spamdyke ( This is a great tool for a number of reasons:

  • it works
  • it does not require patching qmail
  • it's free
  • it brings a lot of functionality to the table that is just not in the standard qmail install (patched, qmailrocks version, etc.)
From the site:
spamdyke is a filter for monitoring and intercepting SMTP connections between a remote host and a qmail server. When a connection is established from a spam source (as determined by the active filters), spamdyke will reject the email -- qmail never sees it.
Beyond filtering, spamdyke offers a number of other features:
  • spamdyke supports SMTP AUTH and will even provide SMTP AUTH to an unpatched qmail server.
  • spamdyke supports TLS and will even provide TLS to an unpatched qmail server.
  • spamdyke provides much better, much more complete logging than qmail, using syslogd.
  • spamdyke can log all SMTP traffic to aid troubleshooting.
  • Best of all, using spamdyke does not require patching or recompiling qmail!
Installation is trivial, and it works out of the box, as it were.

Some other qmail related links that might be of help to you if you are looking for a solid, easy to maintain system:
  • FreeBSD Rocks! ( - a step by step to installing qmail on FreeBSD. This is an excellent successor to qmailrocks.
  • Setting up mailhubs ( - how to set up multiple incoming servers all delivering mail to a centralized mailbox machine. Excellent way to share the load on busy sites.
There are many other resources out there, and most of them are linked on the main qmail site (