We are deploying Exchange 2007 into a network of about 60 workstations. We currently have 8 total servers: 3 DCs comprised of (1) x64 2003 server and (2) W2K DCs plus there are 5 member servers. We are currently running Exchange 5.5 on a 2000 server that sits in its own child domain. An AD connector appears to be installed. On the parent domain there is 1 member server that runs Exchange 2000 that appears to be functional and talking with AD but is not handling mail and doesn't appear to do anything. I think that they intended to upgrade but aborted for some reason. I am about to forest prep and domain prep for Exchange 2007. Do you see any problem with the existing Exchange 2000 member being present? Will the FP / DP cause any irreversible problems?
Any thoughts and questions on this would be greatly appreciated.