Restrict Users

Could setup a firewall, blocking ports 25 and 110 for both incoming and outgoing.
I can't really see how else you would do it
So you don't want users to use email? A firewall should also stop them from modiying that as well.

Regards,
Jim

I can't see how you could prevent altering E-Mail either but you can prevent deleting e-mail through Exchange and keeping it on a Network Share and not making it available Locally but through OWA where they can just view the e-mail but not actually alter it though they can still download it and alter and resend if they want to but you would then have a copy of the alterations and sent e-mails.

Other than doing things that way I don't think that under a Windows System you can prevent this from happening.

Col