We have 2 Domains:
The old one is "xyz.com" and is running on a 2000 domain controller that no one authenticates to any more. AD is in 2000 native mode. This domain is a listed domain in "whois" with networksolutions.com and I feel we really should be using it.
The second one is "xyz.local" and is running on two 2003 domain controllers in mixed mode. All the staff authenticates to this domain. One of the DC's also runs Exchange 2003 but is not yet our primary mail server. It's just there for testing before we switch over from an older legacy system.
What I want to do is to move everything back to the xyz.com domain. For all practical purposes I don't even need to have xyz.com's DC on as it's an older box that is not reliable.
The Exchange application could be un-installed if that would make things more do-able.
There are 3 other member servers still running 2000 that will be upgraded to 2003 soon.
I will be having external OWA clients logging into Exchange in the future so will need to set up CA and SSL then.