Embed Notice

Taking a stroll through my spam folder, I saw a bunch of legitimate messages from people and companies with their own domains, that are not publishing DMARC and SPF records. Surely everyone (and by everyone I mean Google) is rejecting their mail? How do they not realize this?

Then I noticed that one of them was received *from* gmail, so their mail probably works fine so long as they only mail gmail users. But another was via Yahoo, so that doesn't track.
https://jwz.org/b/ykk8