Set up new security on an existing system. I add the first new user, nothing special, and get a screen full starting with: Fatal error: Uncaught Swift_TransportException: Expected response code 250 but got code “535”, with message "535-5.7.8 Username and Password not accepted. For more information, go to 535 5.7.8 etc etc etc.
This is on development machine. I’m obviously missing something.