CPUU error: "Switch message was not found." (4211559)

The CPUU log contains the message: Switch message was not found..

The Mail Source Agent (MSA) log reports that the mailbox has been switched and that the hidden message has been written into the mailbox. The console indicates that the mailbox has been switched as a green checkmark is displayed next to the mailbox.

A manual unswitch and switch of the mailbox works with no errors.  An investigation of the EMWMigration.log revealed that there were no errors and that the switch message was written to the source mailbox.

A check of the source mailbox with MFCMAPI confirms that the hidden message has not been posted or written into the mailbox.

The Outlook profile is using a Personal Folder File to deliver new mail to. On opening Outlook this personal folder is the default mail location and not the mailbox. CPUU cannot find the hidden message in the Personal Folder.

Switch the profile from pointing to a personal folder file back to pointing at the mailbox and run CPUU again.

As noted in the Problem Description above, MFCmapi is also fooled by this issue.  If when using MFCmapi a new profile is created during logon (Logon and Display Store Table from the Session menu) and the LEDN is used instead of the mailbox alias, the profile will resolve to the mailbox and not to the personal folder.  The hidden switch message can then be found.