Get someone else to host it. Or don't play in it. I wouldn't play in a pbem game where the GM was also a player, no matter what safeguards were in place.
You could set up a game using one of the electronic judges, letting it do all of the adjudication.
Well, this is just for our group of gaming friends and I wanted to provide some fun out of our weekly boardgame nights.
So I'm pretty sure they'll trust me as a playing GM and if I tell them the only way we can do it is by them mailing me and me promising not to open the mails until a certain date, I'm pretty sure they're OK with that.
I'll look at the links, thanks.