@evan Gmail is still a big enough gorilla it doesn't have to follow rules, though. When it classified *my* server as spam, it sent no diagnostic messages. Just stopped accepting mail, inconveniencing nobody except the people I try to email. And me.

Meta will do the same for the fediverse. Embrace, extend, and attempt to extinguish, because even a tiny additional shard of market share is worth any amount of irritation for others, if it doesn't cost me anything.