Building a secured open source mail system for Small Medium Enterprise (SME)

Nowadays, most Small and Medium Enterprise (SME) need to host their own mail servers for their global business needs. Nevertheless, the growth of viruses/worms is enormous and the security solution for them is getting more complex and costly. This document aims to provide the possibility of using secured open source mail system solution for SME. It begins with the selection of the current open source mail system. A typical scenario would be used for the risk assessment before setting up the mail system. The mail system would be equipped with all necessary packages for anti-spamming, anti-virus, content filtering & etc. Thereafter, various testing methods would be used to verify the mail server are well protected and secure. Lastly, the reader would be able to know how to implement a secure open source mail server in a typical SME environment.