SpamAssassin kills spam dead on its track!

Got the new spam filter for our Microsoft Exchange server up and running in the office network for a few weeks now, and I'm totally thrilled as to how well it works straight out-of-the-box, so to speak. SpamAssassin is another testament to the power of free and open source software development.

There are a couple of available SpamAssassin plugins for Exchange Server, but I used Christoper Lewis'
Exchange SpamAssassin SMTP Sink
(Thanks, Christopher!) since it worked best for me. Initiallly, I installed SpamAssassin on the same server as the Exchange Server, but soon found that Perl's performance on Windows platform was really bad. Some of our incoming emails eventually arrived at their recipient's inbox six, eight hours late. So I switched to running it (spamd) on a Linux server, and then made the Exchange sink connect remotely to the SpamAssassin daemon. It seems sort of counter-intuitive, doesn't it, when you first think about it, but the performance is much, much better this way. Perl likes being run on Linux better than on Windows.

So far, the spam filter has caught about 99% of the spams that have come through our server. That's an acceptable success rate--And no false positives, unlike the spam filter that we've tried previously. The installation was relatively straight-forward, a credit to the documentation. I also like the fact that in addition to the usual DNS black list lookup approach, which other typical spam filters use, SpamAssassin's Bayesian filter weeds out spam contents quite well. That's smart stuff! And that's with me barely scratching the surface of functionalities after a couple of days of playing with it, without training the filter whatsoever.

Who would have thought ten, fifteen years ago that spam e-mails would become such a big problem to our corporate netizens. They are a complete waste of bandwidth, not to mention a waste of every body's time spent in deleting them. But thanks to great open source tools like SpamAssassin, coupled with strong legislation from our law makers, we'll soon put an end to this net parasite yet.

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