The cause of this behaviour is due to the folder type being set as an IMAP folder in Exchange. To correct this issue simply follow the below procedure (as always after making the required backups):
Download and Install ExFolders:
- Confirm you are running at least SP1 for Exchange 2010
- Download ExFolders for Exchange 2010 (SP1+) from http://gallery.technet.microsoft.com/Exchange-2010-SP1-ExFolders-e6bfd405
- Install the ExFolders utility by running the registry file contained within the ZIP and copying the ExFolders.exe file to the Exchange bin directory
- Run the ExFolders.exe file
- Click on File - Connect
- Connection Type should be set to Mailboxes and Connect by set to Database
- Click on the Select button next to the "Global Catalog" section. Enter a DC running the global catalog role
- Click on Select next to the "Database(s)" section and select the required exchange database
- Click OK, at this point you should see a list of mailboxes contained within the database(s) you selected from the previous step
- To run modifications for all mailboxes simply highlight the Mailboxes root, otherwise highlight the user mailbox you wish to update
- To enable logging for troubleshooting purposes click on Tools, Options and enable both the "Enable logging to file" and "Enable extended logging" then click OK
- Click on Tools - Custom Bulk Operation then paste in the following into the Overall Filter section : (&(0x3613001E=IPF.Imap))
- Now click on the Add button and on select "Other folder properties" on the Operation Type prompt
- Click on the Property drop down list and select "PR_CONTAINER_CLASS : 0x3613001E"
- Enter the following into the Value field : IPF.Note and click on the Add button
- Click OK and OK again
- The update process will now run, correcting all IPF.Imap folders contained within the selected Database / Mailbox to the standard IPF.Note format
Note that it can take a few minutes for Outlook to update the folder type information.
I hope this helps you out.
