Can anyone recommend an Antivirus solution for Linux, running Sendmail?
Martyn uses amavis with Postfix I think, for the ALUG.org.uk mail server. I don't know of anything that will scan files downloaded from the web.
Me, I think fixing client problems by hacking the server stinks. You'll still only get people running stuff not got through the means covered and they'll be complacent. Linux virus problems are still rare (you only installed GPG-signed packages of software from recognised sources, right?) and most other problems can be taken care of by keeping your system patched up to date.