Well I just checked, and you have exactly the same settings as iPrank, so it's not a problem with any of the options, or group membership (as you are both powerposters).

Based on your email address, I'm guessing that there isn't a spam filter (or at least, it's one you manage yourself), so the issues that several other members have had with email services isn't going to be the problem either.

..unfortunately that means I personally can't help on this one, hopefully Brad/Joe will have something more to add.