Moving a mailbox from one forest with Exchange 2007 to a second forest with Exchange 2010 is always scary, even after extensive testing. However you have to do it at some point. Here’s what you see at both ends.
Start with the Prepare-MoveRequest.ps1 command:
.\Prepare-MoveRequest.ps1 -Identity <distinguishedname remote user account> -RemoteForestDomainController <remote dc> -RemoteForestCredential $RemoteCredentials -LocalForestDomainController <local dc> -LocalForestCredential $LocalCredentials -LinkedMailUser -TargetMailUserOU <distinguishedname local ou> }
When successful, run the New-MoveRequest command:
New-MoveRequest -Identity <distinguishedname local user account> -RemoteLegacy -RemoteGlobalCatalog <remote dc> -RemoteCredential $RemoteCredentials -TargetDeliveryDomain <domain.local>
This will queue the MoveRequest and if there are no other MoveRequests running, it’ll change to InProgress and start moving the data. When it’s all done it will show that it’s completed.
During the data move the mailbox can remain open. The changes made during the move will be copied afterwards.
After a short while Outlook will presented the user with a dialog: “The Microsoft Exchange administrator has made a change that requires you quit and restart Outlook.”. Restart Outlook and see that it’s connecting to the new server and forest. Experience shows that it might take a couple of minutes for the connection to the new exchange server to be made.
I’ve got to say that MS made this process quite unobtrusive! Kudos for that!