Question : Lost access to Exchange 2003 mailboxes

I have a user account that had access to every mailbox on our Exchange 2003 server. All of a sudden, I cannot open any of the mailboxes. It looks like I still have access, but the message I see when I click to open the mailbox in Outlook is:

The set of folders cannot be opened. The information store could not be opened.

I recently created new information stores and moved the mailboxes over to them, but if I look on the security tab for those information stores, the account still has access.

Answer : Lost access to Exchange 2003 mailboxes

Is this account an exchange full administrator?

Thanks
Shaba