Exchange 2003, SP2. Outlook 2003.
I have a secretary who, for the past year, has had no problem opening up her boss's mailbox through her Outlook (it is an Additional Mailbox) on her Exchange account setup.
As of this morning, when she goes to do this, she gets an error:
"Unable to expand the folder. The operation failed. An object could not be found"
No errors appear in the Exchange server event log.
I have removed and then readded the addtional mailbox, with no change.