How often would you be able to detect acceptance-but-non-delivery of your emails to office.com-hosted emails?

Now watch the goal post moving at light speed. This site is by business for business. They can't stand self hosting. Saas or bust. No matter how much time you spend demonstrating the opposite the next time someone mentions email they'll get a backlash. It's mind boggling how it plays out the same every single time. But give them a saas that returns the next integer for $19.99/month and that "creator" will be praised for their hard work. :)