The default setup of #chatmail is for open signups (anyone can get an address) but some operators implement a private signup protocol and that's fine and easy enough to do because https://github.com/deltachat/chatmail/ is a small machine.
Chatmail addresses should be abundant and safe to use for anyone , and cheap to operate with basic skills .... A few thousand chatmail routers might already cover adresses for 10 billion people, with less resource/energy usage than a single VC funded LLM startup :)
@delta hell yeah