Domain Rename's are possible only with Exchange 2003. After you perform the Active Directory rename using the domain rename tool RENDOM, the next step is the fixup the Exchange 2003 attributes using a tool called XDR-Fixup.
XDR-Fixup is not supported on:
- Exchange 5.5
- Exchange 2000
- Exchange 2007
- Exchange 2010
What happens if you have an Exchange 2003 environment that you have just done an ADPrep to prepare the forest for Exchange 2010? Can you still proceed with an Exchange 2003 domain rename?
The answer here is no, the Exchange schema extensions must be that of Exchange 2003 SP2 (no higher).