Good list of techniques. Some of them aren't fully evaluated yet. Definitely worth considering.

This is very very centralized. No good surprise here unfortunately... and still email is really tough to fully self-host.

A good list of tricks to ease the pain with email hosting. I use some of it to deal with the delivery pain.

The sad state of self-hosting emails.

This mistakes are indeed widespread too much for my taste.

Despite all its flaws and the regular claims of its death, email keeps being a central part of our collective infrastructure indeed. Clearly it's still here to stay.

Always wanted to try this particular way of dealing with patches. But none of the projects I contributed to so far work in that mode.