While sounding good in theory, it changes a dynamic in practise. In particular reading a mail would now require connecting to the sender's systems in order to

While sounding good in theory, it changes a dynamic in practise. In particular reading a mail would now require connecting to the sender's systems in order to get the message. That would then give them read confirmation, confirmation that your address is valid, location information (geoip etc) and an opportunity to deliver different content when you request the message versus the stub that was sent announcing it. As is usual with these kind of proposals, you'll find it ticks many items on the checklist: https://craphound.com/spamsolutions.txt https://craphound.com/spamsolutions.txt