Antivirus?

[Jonathan Smith]

We're looking at creating a "gateway" mail server to filter mail sent 
to our regular mail server.  Basically what this machine would do would 
be to accept mail, scan it for viruses, then forward the mail to our 
main mailserver.  There's currently no anti-virus solution for our main 
mailserver and I can't just replace with a linux box since that will 
break compatibility with our user database system (we'll have no way to 
automatically add/remove mail accounts).

Is anybody doing anti-virus scanning at the mail server using a linux 
based product on PowerPC hardware?  If so what are you using?

Thanks
Jonathan Smith