I'd like to configure my (CentOS 6.4, Apache, Postfix, Dovecot) ISPConfig servers with the best practices to fight spam. There are so many articles in HowtoForge and elsewhere, that I'm not confident that I can choose which tutorials to follow so that I can best configure my ISPConfig servers. Can anyone suggest which tutorials I should follow to configure a general-purpose hosting ISPConfig server to fight SPAM?
Here is a current tutorial for hardening postfix: http://www.howtoforge.com/hardening-postfix-for-ispconfig-3 Please note that its very strict and the use of e.g. postgrey will slow down the arrivalof the first email that someone sends to you. The tutorial is for debian but it should work similarily for centos.
