As someone who was on a team that got these "?" emails quite a bit, it isn't the email that was the problem. It was the culture that you will drop whatever you are doing to answer this one very specific question that was the problem.

Now my team had a very good manager who knew the system and pipeline. So if he was 95% sure he knew the answer, we never got the email. If he didn't, he would forward it onto the oncall. And the oncall might forward it onto someone else if they were busy with a Sev1/2 issue.

But it was expected that you would drop what you were doing and answer. I've seen devs get up during the middle of lunch and go back to the office to answer a Bezos question.