I saw this statement awhile ago, and I'm bit confused about how it works.
Suppose you have an email server that can only receive 3 emails every minute, and additional emails are filtered out. (Aside: It's not clear to me if every minute is disjoint if it this is a rolling 1 minute window, but I think it's the former.) The emails received by this email server are sent to a single person. Now it is stated that this condition guarantees that the person won't receive more than 5 messages every 10 seconds, though I don't see how this is possible if my aside is correct?
Here's an example that seems to contradict the premise. Suppose in the first minute you have emails that come in at the $58, 59, 60$ second mark, and in the second minute you have emails coming in at $61, 62, 63$ mark. All these emails will be processed by the email server, and all these emails are also within a 10 second interval, contradict the premise. Am I missing something here?
If my aside is incorrect, and it's the latter where you have a rolling 1 minute window, then I think the premise may be correct, though there should be a stricter condition? It seems the stricter condition is that the person can't receive more than 3 messages every 10 seconds, otherwise it violates the 3 emails every minute criteria.