Moving Exchange to another Domain

In a plan to migrate our network to AD I need to migrate user mail data on an Exchange box in Domain1 to Domain2 which will be W2K AD. Is it possible to bring up a seperate Exchange server in the new domain, recreate users with the same usernames (passwords are not important) and then copy the user mail from the Domain1 Exchange server to the second Domain2 Exchange server? If not, how would you suggest I move mail data from the original domain to the new domain? The only restrictions are that usernames have to be the same but passwords don’t. All client workstations will be manually added to the new domain. I know I can use addusers.exe to bulk migrate the use accounts but I’m not sure about exchange mail.