> For every transactional email I need to send out - registration, account recovery, and email change verification - the user always initiates this by submittin

> For every transactional email I need to send out - registration, account recovery, and email change verification - the user always initiates this by submitting their email address, and it will at that time be available to the backend to perform the needed action. This sounds like terrible UX, not to mention email use cases not initiated by the user. I really think you'd be shooting yourself in the foot by setting up a small site with this philosophy because you don't need emails right now