Version 1.0

Author: Falko Timme

Last edited 05/31/2007

The last few weeks have seen a dramatic increase in spam (once again). Estimates say that spam makes now up for 80 – 90% of all emails, and many mail servers have difficulties in managing the additional load caused by the latest spam, and spam filters such as SpamAssassin do not recognize large parts of that spam as they did before. Fortunately, we can block a big amount of that spam at the MTA level, for example by using blacklists, running tests on the sender and recipient domains, etc. An additional benefit of doing this is that it lowers the load on the mail servers because the (resource-hungry) spamfilters have to look at less emails.

1 Preliminary Note

This is just a quick guide showing you how you can configure Postfix (2.x and 1.x) to block spam before entering the server. It’s more or less self-explanatory. However, after applying this to your own mail server, you should check the mail log to make sure that no legitmate mails are blocked.

You should also take a look at this guide: http://www.howtoforge.com/virtual_postfix_antispam

And this category: http://www.howtoforge.com/taxonomy_menu/1/78/24 has some more great anti-spam solutions.

Continue..

~LC

Technorati Tags: Postfix, Spam