Removing specific messages from your Exchange Server
In this post MSExchange Team explains how to remove messages from mailboxes, public folders and queues in different versions of Exchange Servers, they also go through the process to act proactively using Transport Rules.
Ever so often, an Exchange administrator faces a situation where messages that fit specific criteria need to be removed from a large number of mailboxes or from Exchange transport queues. The need may arise due to some sort of mass mailing, a message sent accidentally to a large distribution group or individual recipients, or it could be one of the steps required to be taken as a part of cleanup efforts after a mass-mailing virus outbreak (although the latter have been increasingly rare and generally taken care of by Exchange-aware antivirus scanners).
Read more at source: http://msexchangeteam.com/archive/2010/10/27/456739.aspx