I need an email client that will block certain attachments.

I need to set up a stand-alone email terminal and I’d quite like to be able to block attachments of certain types (.exe, .com, .vbs etc) - I can (and will) install antivirus software, but I could still be hit by a virus that is so new that it’s not in the latest update.

Is there a client out there that can be set up to filter and delete attachments by extension?

Pretty much any of them will, Entourage, Outlook, eudora, they can all do this

Also, I know Zone alarm can rename VBS extensions but I do not know about others.

Outlook won’t (at least not Outlook 97) - I believe that Outlook 2000 blocks certain attachments that it considers potentially dangerous, but that it isn’t easy to configure.