We are looking at reducing office costs, and one thing our users tend to do is needlessly print emails. We use MS Outlook 2007 with Exchange Server 2003. Is there any possible way to prevent users from being able to print their emails?
As Kyle says, people will figure out how to get around it.
Myself, I can't think of any way to make the system printer(s) not available to only certain applications (especially MS applications like Outlook running on Windows).
If you can't take away their printers, then "people policies" are probably your best bet. "New Company Policy: Keep needlessly printing emails and we'll fire you" generally keeps people from printing emails. :)