Yes, the usual suspects: The Outlook object model, CDO, Redemption, Extended MAPI. I'm also heard of a third-party API that does not require Outlook, but does require $$$$$, but it was so ridiculously expensive as to be not worth jotting down the URL.
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Sue Mosher, Outlook MVP
Author of Configuring Microsoft Outlook 2003
and Microsoft Outlook Programming - Jumpstart for
Administrators, Power Users, and Developers