Hello,
1a) Have I left anything too open to spammers to use my server? Have I
done anything stupid?
http://www.antispam-ufrj.pads.ufrj.br/test-relay.html
Tries to send emails over your server using various techniques. If it
works you have a problem.
http://zy0.de
Shows whether your IP is used for anything stupid.
5) Does anyone here successfully use the rspamd filter for DKIM
Ed25519? I set it up, rspamd was signing with Ed25519, and online
checkers said my DNS was correct, but GMail reported: "dkim=neutral
(no key)".
IMHO ed25519 in DKIM is to new for now.
You can also use https://dkimvalidator.com to test your config.
