So is that why send mail won’t work for sending myself emails about a system? Once upon a time you could do that, but now no more is what I’m reading between the lines, sans a proper mail server??

I layer up. Always pihole, and whatever I can run locally on a machine or browser.

https://docs.pi-hole.net/guides/dns/cloudflared/

Is this not that, or is Cloudflare on the naughty list these days?

Yes and no. You just have to see its beauty to get it. I also have been using it for a long ass time, almost a decade, so I could not even tell even tell you what sites look like with ads.