Why not use CDO for sending email?
I've implemented it before but don't have access to that code at the moment. Try this link:
http://www.rondebruin.nl/cdo.htmThere are also ways to prevent the security dialog. See:
http://www.outlookcode.com/article.aspx?ID=52and
http://msdn.microsoft.com/en-us/library/aa168346%28office.11%29.aspxand
"This article solution: If using Outlook 2003, the VBA code stored inside of the VBA Project of Outlook is assumed to be "Trusted" - this then bypasses the warning messages - then you can call this VBA code using automation of Outlook. "
http://www.everythingaccess.com/tutorials.asp?ID=Outlook-Send-E-mail-Without-Security-WarningThe last link may be your best one, if you are able to access the Outlook VBA environment. Not so useful if you want lots of users to be able to send email as it requires a per-client Outlook VBA routine.
Simon