We are using Symantec Antivirus Corporate Edition with Exchange Option on our Exchange 2000 server (we also used it previously on 5.5) It does an excellent job of picking up viruses in email BEFORE it gets to the user. There are many many options in the version for Exchange 2000, you can automatically have the server send an email to the person who sent the infected email as well as to administrators. We never had much success with the Computer Associates Inoculate It software thats why we switched and couldn't be happier!