> How can nostr be slotted into current email tech?

I'm not sure the question makes sense. Cramming everything into email or everything into Nostr wouldn't be useful. The essential point is that the "shape" of one-to-one, one-to-many, and many-to-many communications are naturally different and are best supported with different UI metaphors -- even if the differences are subtle. Also, "sender-decides" and "receiver-decides" are distinct communication models that require different mechanisms. One might have a single application that could properly serve each of the "shapes," but that would be simply an optimization.

Of course, there are some obvious technical things one could do. For instance, it seems reasonable that one might replace POP with Nostr for last-mile delivery. The result would be something somewhat like IMAP. But, you wouldn't want to replace message transport protocols with Nostr. Email's ability to do store-and-forward routing of messages with an explicit destination is very important for the kind of messages best suited for the email paradigm. Often, those messages require a reasonable guarantee of delivery. (i.e. If I'm sending you a contract, I must be sure that you'll receive it and see it.) I think many of Nostr's other applications can be more forgiving about delivery guarantees and they don't need to ensure that you see all messages that might have been accessible by you.

The big differences are in the user interfaces. For messages that really should have been sent via email, it is reasonable that I should have an interface that provides a lossless, potentially permanent, store of messages both received and sent. And, it is reasonable that the interface include mechanisms intended to ensure that I see everything that was sent to me. But, the kind of communications that occurs in at least in what I think are the existing uses of Nostr is more likely to be ephemeral. While a permanent record of Nostr messages might be useful, it isn't essential in the same way that it is with email.

Many mailing lists are, I think, good examples of something that we do with email but that we really shouldn't. When Google Groups came out, I was really hoping that it would help put an end to many mailing lists. It seems to have had the opposite effect... I'd like to see more of the one-to-many stuff move out of email. The needs are different. For instance, my email system will typically only provide me with messages received since I started using it for a particular list. On the other hand, with many lists, it is useful to be able to view content published before, even long before, one subscribed. Email can't do that. Other patterns can.

But, I'm wandering in this note. The key is that we need to accept that not all messages are the same. We need a variety of methods for dealing with messages having different needs. It is time that we stopped trying to squeeze everything into email, or into any other application pattern.

bob wyman