It would be very helpful for the Gabb user experience if they were allowed some form of email. Almost every school I know of requires their students to use a school email and they communicate important information through that channel. I understand there are risks because of spam mail and communicating with strangers. Perhaps a good solution would be a monitoring system akin to Gabb Messenger where parents can view and approve flagged content before it reaches their child.
Let me know what you think!
