This is due to the "new" security concerns of apps sending mails without user concern.
In order to send e-mails I've tried to use that extended API, but at the end this requires you to have a mail client installed and the extended api will be focused on that client so the day you'll change the client (i.e. from Outlook express to Outlook) it can happen that the program stops sending e-mails.
I've used this class from PJ Naughter: http://www.naughter.com/smtp.html
It works like charm, you don't need to have any client installed and it's easy to use. Only endure to read the code files header where all the dependencies are explained.
You'll get it working in less than nothing.