That's not a well kept secret, that's just a workflow that almost nobody would accept for their email setup which is the center of most people's digital identify and should always work and not be a duct taped construct to save a couple of bucks.
I'll stick to Fastmail, where if something isn't working as expected I can just email them and get a response from a real human.
It's hyperscalable and highly available today, until the API changes.