Sysop Blog

Lately I have been tasked with filtering outgoing email coming from our webcluster. Why does it seem that nobody has figured out how to effectively filter outgoing email from webservers? Every solution seems to fall flat. The best I have seen so far came from a custom plugin I wrote for Spam Assassin that uses Akismet (Sorry if I was pounding on your servers guys) to do the filtering. The Akismet filter worked probably about 50% or so better then the commercial cloud mark plugin that I tried.  Not to mention it caught way fewer false positives then cloud mark. I wish I had my notes still cloud marks false positive rate was over 25% if I remember correctly. This was with all the Spam Assassin rules turned off by the way for testing on cloud mark and akismet.

My current setup is a sendmail wrapper that adds extra environment variables for outgoing email to use for filtering purposes and also does some script logging. This was pretty easy and I can post if anyone is interested. The rather difficult thing was making sendmail auto add the headers for me based on the environment variables since I didn’t want to manually alter the email. Ill post the sendmail magic here later on.

I have a VOIP project im working on right now that has pulled me away from this but when I get back to it I will post more info on what im doing now.