On receiving a new mail, I want to capture its handle , so as to read it's subject. this thing should be done on new mail event?

I want to send mail from "VB form" using default mail client available in the system. I have done it using Microsoft outlook. But I want to give flexibility to the user to use the mail client available on his/her machine? How we can do that? Kiran(grover)Adlakha