Mailbox recovery

Trying to retrieve a folder from a “corrupt” mailbox. I exported the folder to a pst then deleted the mailbox using the Exchange System Manager (2003). I then created a new mailbox for the user and tried to import the pst. The folder is empty. I can see the old mailbox in the System manager but can not reconnect to this user or a new user. Message “object can not be found”. I do not have a single mailbox backup, but do of the full store. Ideas?