Reverse Inbox Management Process

I have a Clients inbox that appears to have had the “inbox management” agent run against it as it is displaying only the last 90 Day’s mail of 3 years mail.

The all documents view shows “inbox” against the documents that are not displayed.

There is no evidence that the inbox management process has been run (i.e. there is no policy and the server document’s section also has not been completed)other than teh fact that anything older than 90 days “disappears” from the inbox.

Is there some way to reverse the effects of the Inbox management process to re-display all items that should be in the inbox?