This is news to me. Someone has released a user-friendly email solution
based on SMTP or some other protocol that
supports friending and does not deliver mail from non-friends?
Yeah, AOL child mode, only accept mail from addresses in your address
book. It's been around for at least two decades.
Perhaps it's time to resurrect the ASRG list, where we had discussions
like this all the time.
R's,
John