Our Exchange experience started with an Exchange 2003 server. We recently installed an Exchange 2010 server and all seems well on that front, so I'm preparing to decommission my Exchange 2003 server. User mailboxes have long since been moved to the new server. What I'm wondering about is the "Microsoft System Attendent", SMTP*, and SystemMailbox* mailboxes, which are the only ones visible now in ESM.
Is there any reason to migrate any of these three mailboxes to the new Exchange 2010 server? I'm assuming not in the case of the SMTP* mailbox, but I don't know about the others since I'm unclear on their purpose. Also, is there such a thing as "hidden" mailboxes I need to worry about?
The only other decommissioning issue that I'm a bit unclear on is in regarding to RUS. As I understand it, there isn't a RUS in Exchange 2010, at least not in the sense there was with Exchange 2003. I have read that to remove Enterprise RUS I need to use ADSIEdit. In this scenario (migrating from a single Exchange 2003 server to a single Exchange 2010 server), is it appropriate for me to remove the Enterprise RUS before shutting down the Exchange 2003 server for good?
Thanks
Dave