Linux Babe published a tutorial about setting up Amavis and ClamAV on Ubuntu Mail Server.
Setting Up Amavis and ClamAV on Ubuntu Mail Server
This is part 10 in the Ubuntu mail server from scratch tutorial series. In this article, I will show you how to use Amavis and ClamAV to scan viruses in email messages.
Setting Up Amavis and ClamAV on Ubuntu Mail Server - LinuxBabe