While normal Outlook access appeared to be fine. OWA was giving the following error message for some mailboxes:
The item that you attempted to access appears to be corrupted and cannot be accessed.
The temporary solution (though a little difficult to believe) was to access OWA using OWA Light, just ticking the checkbox when logging in displayed the mailbox.
From Micro$oft on this issue (not sure why the MS engineer uses comic sans – I didn’t think there was anything amusing about it):
Previously I have found that deleting
and recreating the mailbox has resolved the issue (export mailbox to PST
first). If it has failed on calendar reminders, we found that opening the
mailbox with Outlook 2003 with /cleanreminders switch has also worked – when we
logged onto the mailbox with outlook 2003, we also changed the calendar view
from ‘Day, Week, Month’ to ‘By Category’ then back to ‘Day, Week, Month’.
