OpenBSD Journal

More Anti-Spam Stuff

Contributed by jose on from the cuttin-the-cruft dept.

I've spent a lot of time in the past several years administering email systems for people. As such, I have spent a lot of time thinking about spam, and some research recently has looked for better ways to track and kill spam.

A good writeup on spam filtering was written in 2001 by the guys at Munts Technologies. With a little bit of work it can easily be adapted to a current system. The razor agents ports in the tree are also worth looking at using and setting up.

Lastly, through much of my research at trying to improve this process, I found that Baysean filtering, such as is implemented in ifile is an extremely effective way to filter spam and other annoying emails. Additionally, you can turn this process into finding interesting things in your inbox and categorizing them appropriately.

Definitely worth checking out if you deal with lots of email every day.

(Comments are closed)

  1. By Anonymous Coward () on

    You might want to look at this lwn article about Bayesian filters too (specifically bogofilter)

    1. By Anonymous Coward () on

      There was a pretty long thread on the Postfix mailinglist about this topic. Google if you're curious...

  2. By aw man.. () on

    I've set up a series of systems that gateway incoming mail for a pile of our clients. postfix UCE rules and rbl lookups knock off about 30% of all incoming connections, followed by spamassassin+razor tossing another ~10% from those that made it through postfix. That's an average of around 40% of all incoming mail being tossed as SPAM. And the frail exchange box is safely hidden from direct contact with the internet..

    Mind you occasionally the exchange box dies and once resurrected requires restarting of service for every ~20 msgs postfix blasts out with the flush command, making life a little tedious to get back to normal....


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