Migration Manager can automatically switch a mailbox once its content is fully synchronized, or a user can be switched manually by the administrator. Once a user’s mailbox is switched, all new mail arrives at the Exchange mailbox only.
Public folders and calendars continue to be synchronized throughout the migration until all users are using their target mailboxes. However, it is recommended that the initial public folder and calendar synchronization complete before the first user mailbox is switched. This will ensure that users in the source and target organizations see the same calendar and public folder data.
Once a user’s mailbox is switched, the Outlook profile of that user should be updated by the Client Profile Updating Utility (EMWProf). Normally, administrators should include this utility in user logon scripts for the migration period to ensure that Outlook profiles for the switched mailboxes are updated automatically. In that case, EMWProf will start at each user logon, scan for Outlook profiles, and check whether any of the profiles point to switched mailboxes. If a switched mailbox is found, EMWProf updates the profile so that now it points to the new mailbox on the target server. If no profiles require update, EMWProf quits.
If a user has mail profiles on multiple machines, such as a laptop and a desktop, the profile on each machine will be updated when the user logs on to the machine.
For more information about switching mailboxes and updating client profiles, see the Mailbox Switch and Profile Update topic.
Initially, all incoming SMTP mail is received by the source Exchange bridgehead server. For mailboxes that have been switched, it is automatically redirected to the target Exchange bridgehead server.
In order to optimize routing, you should switch incoming SMTP traffic to the target Exchange bridgehead server when about 50 percent of the users have had their mailboxes switched to the target. To switch incoming SMTP traffic, change the name server Mail Exchange (MX) and/or Alias (A) records for Internet mail.
After this change, all SMTP mail will arrive in the target mailboxes. For mailboxes that have not yet been switched, SMTP mail is automatically redirected to the source Exchange bridgehead server since redirection for such mailboxes is set on target.
After all the data is transferred to the target servers and all mailboxes are switched, you can stop and uninstall the synchronization agents. The agents are:
Clean up the additional SMTP addresses set for redirection purposes and the custom attributes of the target objects used during Exchange migration.
You can use standard Windows utilities for bulk LDAP operations, such as CSVDE, or third-party tools to clean up service attributes used during migration and directory synchronization.
Cleanup of service attributes can also be done by the Active Directory Cleanup Utility for Quest Migration Manager, which is included in the Migration Manager for Active Directory Resource Kit.