Google Groups : microsoft.public.exchange.admin: “To expand on this answer, here are the detailed steps to use for the search:

Do a find in AD Users & Computers:

– Right-click on your Domain name and click Find
– In the Find dropdown, select Exchange Recipients
– Check ONLY Users with Exchange mailbox on the General tab
– On the Storage tab, select Mailboxes on this server and specify the
server name you are trying to remove
– Click Find Now
– Select all of the users it finds, right-click, choose Exchange Tasks,
Delete Mailbox

Thanks,
Richard Roddy
Microsoft Exchange Support

This posting is provided ‘AS IS’ with no warranties, and confers no rights. ”