Please take a look at this Nostr note and the comments below. The Signal/MLS protocol is not suitable as the encryption algorithm for DMs.

Whether a stamp is required is up to the relay operator. The relay run by Keychat requires a stamp, but there are plenty of free Nostr relays out there.

You’re free to use multiple relays at once — whether they’re free or paid. Just long-press your sent message, tap “Raw Data,” and you’ll find the stamp there.

Thanks. Keychat is like a great surfboard for surfing the Internet.