The mailboxes for unified messaging users in Cisco Unity Connection can be moved from one Exchange server to another. You may want to move the mailboxes from one Exchange server to another due to any reason. Consider an instance in which after adding the latest supported version of Exchange server to the existing Exchange environment of your organization, you want to move the user mailboxes to the latest version.
To move the user mailboxes from one version of Exchange to another, you need to update some specific settings for the Unity Connection users. This enables Unity Connection to automatically detect the migration of user mailboxes automatically. If Unity Connection fails to detect the migration of mailboxes, you need to manually replace the existing mailboxes of unified messaging users with new mailboxes on the migrated Exchange server.