This is normal behavior. AFAIK, Exchange does not remove duplicate addresses
from a message.

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Sue Mosher, Outlook MVP
Author of
Microsoft Outlook Programming - Jumpstart for
Administrators, Power Users, and Developers
http://www.outlookcode.com/jumpstart.aspx
>I have external contacts in Active Directory who are in multiple
>distribution
> lists. Users in more that one DL recieve a message for each DL. Is this
> normal behavior? If not can you please point me in a direction to
> correct.
> Thanks, Paul