@xarvos well, gmail effectively is a silo, like twitter or facebook. it's the attempt to restrict the usability of mail under the guise of fighting spam.

@bonifartius I agree with that, but I don't get why you get "gmail users want to be ignored" from that. Furthermore, others confirmed that other mail services such as Fastmail and Migadu also consider OP to be spammer, maybe due to failed DKIM, and that they, self-hosting mail themselves, have no trouble interacting with GMail.