I had a go at this followimg Damien's instructions for 5.5 (I am using 5.1.2).
Clam is working OK. Like Kelvin I needed to force amavis-ng rpm.
I then altered the conf file and ran
/sbin/e-smith/db configuration setprop smtpfront-qmail filter /usr/sbin/qmail-queue.amavis (is this OK for 5.1.2)
then
/sbin/e-smith/signal-event email-update
Everything appeared to be accepted but an email with eicar attached is not being intercepted.
Can anyone suggest how to proceed from here please.
Regards
Brian