@icedquinn make a test one on mine chat.feld.me or the official-ish one run by the devs at nine.testrun.org

If you deploy a chatmail server using their special configuration it will never allow unencrypted messages to be sent out, push notifications work, and account signups are instant / permissionless. Logs scrubbed, data automatically purged server side after X days, idle accounts deleted every Y days, etc. super nice.

My link is in my bio if you want to test. The in-chat apps are great too -- utilities, games