> This is not well reasoned. Sending emails can be easily spoofed, because sending doesn't fully check the identity of the sender as being in control of the email account. There is discussion of various technologies like SPF or DKIM, but those are not universally applied. When they are applied, there isn't universal quality in their application.

I bring up both of these at the end of the post, under "potential limitations." I'm very aware that SPF/DKIM don't do identity authentication, and that they're not universally applied!

This post is best read as a random thought, not an exhortation or formal argument. It says as much in the first sentence.