Currently I have about 40 users using pop3 mail on a p2p network. I purchased SBS 2003. I want to start moving clients onto the new 2003 network.

My problem / question is regarding email. I have added all the current users account to the 2003 box. I have setup a test account on the new 2003 domain. When I send out an email to the current corp users (who are not yet joined to the domain ) , the email stays on the server and doesnt get sent out to the pop3 account who are not yet on the new domain. I understand why this is happening, it's because the users has an account on the Exchange box, so Exchange doesnt send it out via smtp. But the user isnt connected to Exchange yet, so the users dont get the emails. How do I get around this? I will be unable to upgrade all users at once to the new domain.

My thought was to get everyone on the new domain, and just not setup their Outlook to point to the Exchange server until everyone is on the new domain. Once that is done and everybody is authenticating to the new server, I could utilize the pop3 connector service on Exchange and point everyone's Outlook client to the Exchange server.

Or, can I have Exchange send all internal email out to our ISP's smtp server, then back to us? If so how do I do that?

I hope I explained myself well enough.

Any other thoughts or ideas to help get around this?