Deleting the account would be a solution, but it is not as hard a task as you think. Create a copy of the account with a different name. Give yourself full permissions to both mailboxes. Map both mailboxes in your Outlook, and transfer all emails, calendar objects, notes, etc… to the new account. Delete the old account, and rename the new account.

Users on Cached Exchange mode, may have problems emailing to that account until their GAL is updated which happens roughly once a day. That happens because Outlook is still trying to send emails to her old Object ID. Other than that, no other problems in deleting the account and recreating it.