Hey @jimr1, if you still have your ‘more normal’ out-of-the-box install (that does mail.log out automatically, etc) do you think you could confirm that Rate Limiting is not working out-of-the-box.
I have another thread (Mail Rate Limiting broken out of the box (Ubuntu 24.04)) which has failed to get a response. In it I observe that I can set the rate limit on a domain to 2 per hour, and then have no problem sending 3 mails in a row (screenshots and such are in the thread).
Anyway, it occurs to me that maybe that being broken is also a product of my Ubuntu 24.04 .iso, updated to the latest installers. (It’s probably wishful thinking, but if yours works I’m downloading an new .iso.)