Please prefer to make one forum topic per one question, otherwise it’s hard to search the forum.
Your question is about whether you can use the auto-generated email on a Chatmail sever to receive “regular”, unencrypted emails, to sign up for services and stuff?
The short answer is “no”. See
- Public chatmail servers "prohibits sending out un-encrypted messages" but they also prohibit receiving unencrypted messages and nothing mentions that
- https://github.com/chatmail/relay/pull/538
- Is delta chat spam resistant? - #4 by link2xt
- If you’re an admin, you can add some emails that can receive unencryped email: Create a normal email with chatmail (I'm an admin) - #2 by WofWca.