"Infection Detected" - I'm being targetted by trojan spam. Help please!

One of my email addresses is being targetted by spam email many times a day. “Avast Mail shield has detected a threat”. I’m on an iMac OSX 10.7.5 and using Mac Mail. Each spam email has a different originating IP address, but all of them have a zipped trojan. The infection is Win32:Crypt-PWV[Trj]. I’d love to know how to stop this c**p being sent to this particular email address - it’s ‘random_name@email.address.org’ where random name can be anything from root to accounts to eric, etc. This is the latest originator: from [76.72.172.156] (port=35381 helo=lvps3.ardanhosting.com)

How do I stop this please?

Try to block the sender in Apple Mail. Reply if it helps or doesn’t help.

Cheers,
Hello