> (with DMARC signatures and other modern email practices) DMARC does not provide signatures, DKIM does. DMARC adds the DKIM 'alignment' requirement. Meaning that not just any DKIM signature will do, the public key (the DKIM DNS record) must be published under the administrative domain (the part after the '@' in the sender address). DMARC also mandates SPF alignment (not that your should rely on SPF), meaning that th…
Oh come on, in terms of protocols, that's modern.
Your other points have merit but that's just a pointless dig at the author.