Can I bring online a 2nd MailStore server that has SP1 installed on it, even though the rest of the Exchange 2007 Enviroment is still RTM? Thanks Stein_97

Whilst I'm not saying that it won't work, Microsoft recommends that you upgrade your Client Access Servers first when upgrading to SP1, so personally I'd be inclined to follow that advice. Why wouldn't you want to be running SP1 throughout?

Mangement wants to do away with the CCR enviroment. My plan was to move everyone from the CCR to a standalone Exchange Server, then rebuild the other servers has standby. I guess I could apply SP1 to my CAS server but not the Mailbox Server. Thanks for the info..... stein_97