What is it that you're trying to test? Whether the mailbox can send mail or whether the user's copy of Outlook is set up correctly? Those are two different things. You could take care of the former by creating a profile for that mailbox for yourself and sending a messag or by using CDO.Message on your own machine.
I can't think of any good automated way to checking the client workstation configuration. Any script you write to automate Outlook would be subject to security prompts, which the user either wouldn't know how to deal with or (best case) would click No because the source is unknown.

Signature
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
> Hello,
> I'm wonder how can make Outlook to create and send a message from user
[quoted text clipped - 5 lines]
> the point I have no idea how can workaround it.
> Thanks for any advice