@supratic posted about this a couple days ago #1552117 but here is a description of the project by Bitshala.

On the one hand, this isn't terribly novel: I think it's pretty much just a bridge from nostr to email clients. But, on the other hand most (almost all?) email is hugely centralized -- starting to give people tools to take control of their storage and identity away from some single provider might be useful.

Mailstr is an attempt to rethink email around Nostr's model of identity, ownership and interoperability.

Traditional email ties your address, inbox and identity to a provider. Mailstr takes a different approach: your Nostr keypair becomes the foundation of your identity, while an email alias provides compatibility with the existing email world.

1. Identity is separated from the provider

Your identity is tied to your Nostr keys rather than being created and controlled entirely by an email provider. This makes the identity portable across compatible services and clients.

2. Email remains compatible with the existing internet

You still get an email address that can communicate with conventional email addresses. The goal is not to force everyone onto Nostr before they can communicate with you.

3. Your messages can be cryptographically protected

Nostr-Mail uses Nostr's cryptographic keys and NIP-44 encryption to protect message content. Messages can also be signed so recipients can verify the sender.

4. Storage and infrastructure become less tightly coupled

Instead of treating one company's servers as the permanent home of your mailbox, the architecture can use Nostr relays and standard email infrastructure for different parts of the system. This creates a more modular model where the client, identity and storage layer don't necessarily have to belong to the same provider.

5. The protocol becomes more important than the application

This is perhaps the biggest idea.

If the protocol is open, you don't need to trust one particular interface forever. Different clients can implement the same protocol and access the same underlying communication system.

That is the Nostr philosophy applied to something people already understand: email.

So the simplest way to describe Mailstr is:

Mailstr is a bridge between the old email world and Nostr's open identity and cryptographic infrastructure, designed to make email more portable, private and interoperable.