OpenBSD Journal

More Sendmail AntiSpam Information

Contributed by jose on from the ham-vs-spam dept.

Just a few more ways you can protect your mail infrastructure using OpenBSD and Sendmail. Free, high performance, reliable, secure ... if you run a mail server on OpenBSD, you have a lot of methods available to protect people against spam (and mail delivered viruses and worms).

Paul Graham's original "Plan for Spam" piece , which led to the creation of tools like bmf and ifile , works on the principles of Bayesian filtering. Simply put, interesting words are used to classify the email into its category, including "spam or not". He's written down his thoughts on Better Bayesian Filtering which will be worthwhile to study, as well.

Sendmail can be used, in conjunction with Milter , to filter spam during processing. Bogofilter has been adapted as a milter , removing the need for external processing via procmail. Other milters include MailCorral , which can work with SpamAssassin, spasm , a highly configuration spam filter with a variety of options for actions and rule imports, CanIt , yet another milter tie in, and a SpamAssassin milter , removing the need for external SA handling (which can speed things up on a busy server).

All sorts of research goes into spam (it is, after all, a slippery text processing problem), including MEF and even the fruits of the MIT Spam Conference .

(Comments are closed)

  1. By Anonymous Coward () on

    Has anyone got Bogofilter to work on OpenBSD? I couldn't get the thing to compile. I don't remember what the problems were. Just curious if others got it working.

    Anyone know if bmf is dead? There hasn't been any activity since November.

    What other Bayesian filters have you tried? I like how bmf works nicely with procmail. Anything else I should look at?

    1. By Anonymous Coward () on

      bogofilter compiles fine.
      The only problem might be the berkeley db stuff. It seemed however to be easy fixed by symlinking db3.h to db.h like this:
      ln -s /usr/local/include/db3.h /usr/local/include/db.h After that, just do
      configure --with-db=/usr/local

      1. By Anonymous Coward () on

        Ah yes, now I remember, the db stuff. That was the problem. Thanks for the tip.

  2. By Throstur Jonasson () on

    The anomy mail tools can do lots of filtering on inbound mail. More than spam related they can be used to defang bad HTML from emails and so forth.

    1. By mirabile () on

      Well, we put our site official, so I can tell you
      the hRef of my BMF+sendmail tutorial:

      Please feedback; I'm using it successfully here tho.

      1. By xsa () on

        the uri to this tutorial has changed due to our new content negotiation policy:

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