Hey Robert, we made the Outbox folder visible in MAPI a while ago.  I'm not sure the exact date but we made it visible about 1-2 months ago.  If you don't see it in the normal email folder view then try switching to the Folders view (should be in the '...' menu next to tasks or notes in the bottom left of Outlook) and see if you see it in there.  If you still don't see it then there's something not right with the folder sync and I'd advise you to open a ticket for it.