OE Duplicate Remover
If you use Outlook Express for your personal or business mail you will, no doubt, have encountered duplicate email messages. The "Outlook Express Duplicate Message Remover" will automatically find and remove duplicate messages. The OEDMR will (a) find duplicate messages in any folder or group of...
http://ajsystems.com/files/oedmr-setup.exe - 2Mb - Download - Screenshot

Duplicates Remover for Outlook
Duplicates Remover for Outlook is a powerful and flexible tool intended for the search and processing of duplicates in Microsoft Outlook folders. DRO process contacts, notes, tasks, journal and calendar items and appropriate type Microsoft Outlook folders. ... Duplicates Remover for Outlook is fully compatible with Microsoft Exchange Server and may be used to process public folders on the server. ... A duplicate found can be: marked with a flag, deleted, copied or moved to any folder you choose.
http://www.mapilab.com/files/remove_duplicates.zip - 2Mb - Download - Screenshot

Duplicate Email Remover
Duplicate E-mail Remover is powerful and flexible tool intended for the search and processing of duplicated mail messages in Microsoft Outlook folders. DER processes both email messages and posts in mail-type Microsoft Outlook folders. You can use Duplicate E-mail Remover to find mail message... Duplicate Email Remover is fully compatible with Microsoft Exchange Server and may be used to process public folders on a server. ... Using the priority system, you can specify, for example, that of the two identical messages stored in the folders "Important Letters" and "Temporary Folder", it is...
http://www.mapilab.com/files/duplicate_remover.zip - 2Mb - Download - Screenshot