Mailing

Card: https://trello.com/c/zp8ibqBS/11-email-notifications-no-configuration-initially-send-an-email-notification-to-everyone-whenever-a-board-is-created-a-card-is-crea
No actual tests for this behavior. Even though it is extremely important, this line is also straightforward and directly from Rails.

Testing it on an integration test would have little value, in my opinion.