I know how email works but it sure didn't help me understand the fediverse.

It's just one thing in email servers functioning that is similar in the fediverse, everything else is not similar. It is just confusing to compare the two to anyone not yet knowing how the fediverse works IMO.

"It's like the postal service!"

"It's like the internet!"

Just say it's like reddit (or a social media) but free and open and anyone can have/make one, or use an existing one. For free.

/Rant off