Disabling "reply to all"

Is it possible to disable the "Reply All" function for e-mails originating from a specific group of users or e-mail originating from a specific e-mail server? Also, is it possible to achieve this for people using both the Outlook client and WebMail? Thanks.

After a quick check through Outlook Express, I am pretty sure the answer to this is NO. The reason is that the client software (email program) handles reply addresses. By the time the message gets to the mail server, the mail server does not know that all the names started out as a "reply to all" action. If someone can tell me that I'm wrong, I'll learn something new. (Which is always good.) But I doubt it.