Hey,
In case you're using Postfix (or wish to replace your qmail install with it) and wish to integrate ClamAV on Plesk 12, I wrote the following how-to:
http://support.oxegena.ch/blog/en/anti-virus-clamav-et-postfix-plesk-12-sur-centos7/42
It's an update of an older article based on 9 and...