From Melwin Enterprises:
sMail is closed e-mail system designed for parents and their children. With sMail, you and your child must use the sMail Reader to read and send e-mail only to other sMail users who are part of your network of family and friends. You, the parent, control who your children can e-mail. Setup is easy and there are no passwords to remember for the children. Simply download the sMail Reader and install it. When it runs the first time, it will ask you for a real Internet e-mail address which will become your parental control account. An activation code and your initial parent password will be sent to that account. From the sMail Reader you can invite others who are not on sMail yet to join and become part of your network. You only need the real Internet e-mail address of a parent. When they join, they can accept your invitation to become part of their family and friends network. Then you and your children send them sMail e-mails. Version 1.0a may include unspecified updates, enhancements, and bug fixes.