Virus checking of incoming mails

Mails detected as "contaminated" are blocked or rejected. This is communicated to a sender (if it is a real person) in the form of a bounce mail.
Depending on the source, the sender and/or the recipient can be optionally informed about the intercepted mail (with current viruses and worms, however, this is superfluous, as the originator cannot be determined anyway due to the forgery of the sender).