We have 3 computer labs. and our instructors would like to be able to teach use of Outlook Express and/or Outlook, but due to usage policies, we are not allowed to use the corporate mail server to give email access.

What I want to do is setup a basic mail server, with about 30-40 email addresses, and have clients able to send and receive email, but I don't actually want to use real email addresses, just something internal. In fact, this mail server does not even actually need any connectivity to the internet.

Anybody have any reccomendations or can point me in the right direction to further research this? I have looked at several tutorials on internal mail servers, but everything I find is to gather mail from another mail server, and then redistribute internally.