“If you are responsible for maintaining an internet-connected
mail-server, then you have, no doubt, come to hate spam and the
waste of resources which comes with it. When I first decided to
lock down my own mail-server, I found many resources that helped in
dealing with these unwanted messages. Each of them contained a
trick or two, however very few of them were presented in the
context of running a real server, and none of them demonstrated an
entire filtering framework. In the end I created my own set of
rules from the bits and pieces I found, and months of
experimentation and fine-tuning resulted in the system detailed in
this article.“This article will show you how to configure a Postfix
mail-server in order to reject the wide majority of unwanted
incoming ‘junk email,’ whether they contain unsolicited commercial
email (UCE), viruses, or worms…”