Non-internet Bulletin Boards would each host message forums but would exchange packages of messages (such as QWK files) via modem so that you could communicate with others connecting to different BBSs around the world.

Such a magical experience back then.

Then usenet newsgroup servers did much the same, (but probably updated more frequently). The peer-to-peer aspect was transparent to the users, so it was good to have just one "place", a newsgroup, where everyone could discuss a subject. But numbers were low enough that it wasn't flooded with messages.