Hi,
I just did a little test to try to help out. I entered 3 emails, 1 was gmail, 1 was ISP email address, and last was a personal domain I own email address. The gmail never turned up. The other 2 came instantly.
I'm not sure if maybe Gmail is on a blacklist with Launchboxs mailer or the other way round.
Have you another Email address you could try?
Cheers,
-SteG-