For now, I would be happy to hardcode it in a file and exec zammad run rake assets:precompile or something. Just like I changed the login page to not show the message “You’re already registered with your email adress if you’ve been in touch with our support team.”
Thanks for your effort. I just found the hardcoded defaults in /opt/zammad/config/application.rb and set email: false for each type. That’s enough for a workaround (until the next update I guess).