These guides are intended to help system administrators understand the capabilities of Postfix. This document is based on features available in Postfix version 2.0 and later, but most of the information here can be effectively applied to earlier versions.
While the guides offer a lot of information about the different capabilities of Postfix, most system administrators looking for information on adding anti-spam capabilities to their mail servers will likely want to start with the Amavisd-New guide. This will give you a good starting point that you can work with while you look at implementing additional features.
Jeffrey Posluns began a set of spam filters based on access lists, header, and body check filters in March 2002. on his own mail servers. Shortly thereafter, he made them available to the public on the SecuritySage web site. In April 2006, SecuritySage merged with another company, and these guides were moved here.
In reading this document, please keep in mind that it is based on the knowledge and experience of the author. Comments, criticism, and updates to any errors and / or outdated information are encouraged and welcome.
In the configurations listed in this document, postfix is installed in /etc/postfix, and all map or filter files are located in /etc/postfix/maps.
You should not implement all the features listed in this guide all at once. Each time you implement one (or more) features, run them for a period of time where you can test their effectiveness. This is especially true for third party filters, as you may inadvertently create internal mail loops.
Remember that no system is perfect, and that your spam filters and antivirus signatures will have to be updated regularly.
Some of the information in these pages may be outdated, as they have not been updated recently. If you find anything that needs updating and would like to submit new text, please send Jeff an email.