http://www.leaddollar.com/
It was a failed attempt at a pay per email program. It failed because there was no way a newbie like me could turn a profit on these emails.
The script was written in php by ME so it may not be the most secure system out there. lol. It does have double optin verification with sessions and IDs.
No admin backend... learn to use phpmyadmin. heh
Anyways.. just throwing this out there. I don't expect to really sell it to be honest but hey worth a shot.