The former. If we can couple an email we receive to a nostr signed account a lot of trust based stuff is solved. A bit like pgp signatures.
Discussion
Aha! That is an interesting thing. Also encryption and security is solved.
The hardest part is to make this compatible with the smtp protocol, or support this for generic email addresses.
Yes indeed! I'll dive into it when I have a bit more time. I'll keep you up to date if you want.