My understanding of federation is that it’s like email. If one server is misbehaving, then they get defederated.
So how come email spam still exists - why don’t spammer domains get defederated? It seems like we’ve got the worst of both worlds, where it’s hard to get your emails relayed when you run a small email server, and easy to get them relayed if you’re a spammer.
Is there anything about Lemmy’s architecture that will prevent this problem?
It will be worse.
And Lemmy is not designed at all to handle spam.
I used to use Kbin.social but eventually it started to get overrun by spam when the servers worked.