I am trying out nostr:nprofile1qyt8wumn8ghj7un9d3shjtnyd968gmewwp6kytcqyqfqnvpy3dadamw96pgpnqy4se0hj5yta90vv7lgpkfrtfuacx2p2qa0ux3 (Delta Chat) and have setup a chatmail relay server.

Delta Chat uses the e-mail protocol for their chat app. This means it's really de-centralised, encrypted and private.

If you want to try it, you can create an account on my server. No personal information is needed for creating an account. (No e-mail, phone number etc).