Server 2003 & Exch 2000

[MrOsborne]

I'm working at a not-for-profit agency with an NT4 network and Exchange 5.5. We've received a copy of Exchange 2000 as well as Server 2003. I installed 2003 on a new server, and then began to look into migrating from Exch 5.5 to Exch 2000. From what I'm reading it seems that Exch 2000 won't run on Server 2003. Can this be true? These two Microsoft networking products, so close together in versions, are incompatible?

If it is true, how feasible is it to run Exch 2000 on NT4? Is this the route I should take?

I'm actually very disappointed. I'd been hoping to move the e-mail burden off of our aging server. I do have one newer server running NT4, though, and I'm hoping I can use that.