It's very unclear how you would ever be able to access this user's calendar folder using Outlook.Outlook has no problems showing these other users' calendars. (I can send you a screen shot...)
I doubt very much that these mailboxes are "broken". It is a consistent problem with all of the mailboxes I've tried. This is a new installation that switched from Lotus Notes two weeks ago, and is set up by professional people.
I've been informed that there are actually two Exchange Servers involved, set up for load balancing, and the server name specified in the mail profile is a kind of alias that implies access to them both. Can this have anything to do with the difficulty of finding the calendars with MFCMAPI?
May I ask a very general question? Like I've said, I always figure that if Outlook can do something then MFCMAPI (and by reverse-engineering and steal.., I mean borrowing, then ultimately my program) should also be able to do it. But are there any "MAPI trace" tools available so that one can gain insight into exactly what Outlook has said to Exchange, and what Exchange replied?