Is this not the logical result of fighting spammers? It’s easier to trust messages coming from mega corp when you know mega corp has invested in mechanisms that ensure their systems aren’t being used to send spam. I certainly don’t like the negative impact on people who choose to self host, but I also don’t see it as an intentional effort to shut out legitimate emails.

Case in point a bit further down in the comments: https://news.ycombinator.com/item?id=43902653