Hacker News new | ask | show | jobs
by ardivekar 3436 days ago
Maybe a two-way 'add contact' feature would be useful, like a facebook friend request.
1 comments

Sure but then it's not standard e-mail any longer.
I remember having a server side system for generating cryptographic email aliases along the lines of:

base64encode(hmac("new-sender@example.com+valid-to+01012018", key))+user@mydomain.com

Truncated to something like fvv544+user@mydomain.com that would only be valid when sent with the from-adress new-sender@example.com (along with some clever magic to avoid email loops! :-)

I think maybe it was authored by ESR (Eric Raymond) in python - but Google only turns up various dkim schemes...

New senders would have their mail held back, and get a "please reply if you are human"-message - a reply (to the "magic" reply-to alias) would release the held mail and whitelist the sender.

A greylist variant of sorts.