New-MailboxExportRequest is processed by the Mailbox Replication Service (MRS) running on a CAS server. It creates a PST in the newer Unicode format (rather than the older ANSI format originally used by Outlook to create its PST files) that should be accessible to Outlook 2003 as this was the first version of the client to support Unicode. Microsoft introduced the newer format to remove some of the problems that existed with ANSI files and to allow for PSTs larger than 1.9GB. I wouldn’t recommend that you create large PST files as I consider the format to be relatively unreliable, but they do seem to be much loved by some users.
No great detail about the reason behind the problem is offered in the KB article. It tells us that the reported error is:
“Unable to display the folder. Errors have been detected in the file “<file name>”. Quit Outlook and all mail-enabled applications, and then use the Inbox repair tool (Scanpst.exe) to diagnose and repair errors in the file. “
All this tells us is that Outlook 2003 has complained when it attempted to open the PST because it considers that some fundamental error is present. Running SCANPST.EXE in this instance is very much a “Hail Mary” pass as the program is unlikely to be able to repair deep-seated damage in a PST. I suspect that MRS has written something into the PST header that causes Outlook to barf; this is just a suspicion and I don’t have any great evidence to prove the point. Perhaps Exchange 2013 will solve the issue.
In the interim, all you can do is use Outlook 2007, Outlook 2010, or Outlook 2013 to open the PST and drag and drop the information from the file into a new PST – hopefully one that is consumable by Outlook 2003.
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