This has probably been discussed at some point, but what's the argument against having a personal relay that a user would only use to receive messages, as opposed to doing NIP-04 encrypted DMs?
If a user could host their own relay (handwaving away uptime and availability considerations), and others could write to, but not read from, wouldn't this be a more natural model? A nostr inbox basically.
Pros:
- you wouldn't need to worry about your messages getting read on all relays, since you'd only write to your destination's personal relay.
- You would get a local data store of messages, data etc.
- Your client wouldn't need to fetch remotely from a third party, just your personal relay
Cons:
- you'd still want to encrypt, and therefore would need a shared key setup of some kind.
- you'd need client UIs to have the notion of "send to this person's inbox/personal relay.
- you'd need to have it open to the internet, therefore probably hosted and the setup that comes with that. I guess this is probably the sticking point, but i like this tradeoff better than encrypted DMs personally.