This white paper outlines some simple, yet effective measures to reduce the amount of SPAM entering your system and some useful counter measures that can be implemented at server level. This paper is aimed at system administrators who manage Linux servers and have an understanding of Linux command line.
It will outline simple but effective measures for hardening your servers, along with some countermeasures.
A link to the home page, or a relevant web site, for each major topic and application discussed will be found in the appendix at the end of this white paper.