Unable to send outlook mails

UPDATE: Situation keeps returning.

Running the db repair command does not fix the problem.

The only solution is to delete (or rename) the database folder at C:\ Usersusername\Appdata\Roaming

It occurs to me that their are several subfolders in that folder so next time I will try deleting/renaming one at a time and see if that pinpoints the problem a little more specifically.