We are getting following error message on the BES one of the blackberry user.

Blackberry Messaging Agent <servername> - "Inbox not found! (username)"

Instead of removing and readding the user, is there way to fix this issue..?

Thanx in advance,

I had this problem and the following steps resolved the issue.

On the BlackBerry device Home Screen, click Messages. Click the trackwheel and select Options.
In the Options list, select Email Reconciliation. Turn the Wireless Reconcile option to Off.
On the computer, open the BlackBerry state database using the Lotus Notes client or Domino Administrator client.
Select the Mail Folders view.
Remove all mail folder documents.
On the BlackBerry device, set the Wireless Reconcile option back to On. You should be able to receive messages on the BlackBerry device.