It's automatic! Click on one of the new icons on your handheld. Doesn't matter. Pick one. Begin a new e-mail message. At the top you'll see, "Send using:
" where
is the e-mail address corresponding to the icon you clicked. You can change that manually in the e-mail message if you want. You can even go in and make it permanently default to another of your addresses that is set up.
Make sense?