It can be done with CDO or Redemption. See http://www.cdolive.com/modifyrtfenabledflag.htm for a code sample.

--
Sue Mosher, Outlook MVP
Author of Configuring Microsoft Outlook 2003
http://www.turtleflock.com/olconfig/index.htm
and Microsoft Outlook Programming - Jumpstart for
Administrators, Power Users, and Developers
http://www.outlookcode.com/jumpstart.aspx

"James" wrote in message ...
There is a "send plain text only" checkbox on the contact form,but it
appears that there is no equivalent property in the Outlook Object Model,how
can I check or uncheck it programmatically?
Thanks in advance.