We are thinking about migrating to a new Windows 2008 R2 forest from our current 2003 AD (not upgrading). Will Exchange 2003 SP2 running on a Windows 2003 SP2 box work in a Windows 2008 R2 AD at the Windows 2008 R2 domain and forest functional level? Also is it true that you cannot directly migrate an Exchange server to a new forest? Instead you have to migrate the mailboxes to an Exchange server already in the new domain. Then repurpose the Exchange server to the new domain and move mailboxes back?

Are you going to go to a Windows 2008 forest/domain functionality or Windows 2003?I can't think of a reason why Exchange 2003 wouldn't work in a Windows 2008 AD Environment. You would still have to prepare the schema and the domain.You're best course would be to stand up an Exchange Server in the new AD environment and migrate to that new org from your old Exchange Server. Since the old Exchange Server is tied to AD accounts etc you can' tjust move your Exchange Server, you would have to migrate it and assoicate it with the AD accts in the new AD world so a migration would be best.BP

Exchange 2003 cannot be installed on Windows Server 2008, but will be supported with Windows Server 2008 domain controllers. Exchange 2003 cannot be installed on Windows Server 2008, but will be supported with Windows Server 2008 domain controllers. http://msexchangeteam.com/archive/2007/08/16/446709.aspxMike Crowley: MCT, MCSE, MCTS, MCITP: Enterprise Administrator / Messaging Administrator

Hi, Please understand that moving a computer that is running Exchange 2000 Server or Exchange Server 2003 to a different domain is not supported: http://support.microsoft.com/kb/812453/en-us Mike