Nevermind! You still have two appConfig sections. The fact that the first one does not have child nodes does not mean that the sections are getting merged or otherwise processed by the configuration...

This is what is wrong. You have two appSettings sections: an empty one (the above) and your modified one. You should keep only one of them.
If you find this answer satisfactory, please add to my...

The point is not sending, but viewing the messages. The messages for a user should carry some information about the receiver. Most probably the MembershipUser provider key. Check for authenticated...

In general set the @Page attribute trace="true" to locate the control. Then you'll easily figure out how to "FilndControl()" it. Read MSDN on FindControl() also. This should be enough!