Stopped working with IT years ago. No time to write RFC's. Always wondered why nobody fixes email instead of creating more and more advanced filters. Fix the problem, not the symptom.
The basic layout is simple. Maybe so obvious that someone has a patent on it....

Email is SMTP. There is no practically way to police it like the article describes. The author simply doesn't know how email works. What we need is a new message standard. An Advanced Mail Transfer Protocol. It should include:
1. Encryption system where mail server publish the public keys. Mail server can also hold the recipient private key. This way an email can easily be signed. My server can check signature to see if the mail really comes from whoever says is the sender.

2. Approved senders AKA friends request. On many social media sites you have the option to only get contacted by those in your contact list. Email should work like this to. I should be able to lock my email account from getting mail from anyone I haven't approved.

This could be implemented with backward compatibility with regular SMTP. All regular unsigned SMTP mail will just be marked as just that. Simple and untrusted. As the net upgrades to AMTP2 there will be a point where the majority is over on the new protocol and spam as we know it will die.