I was talking about https://datatracker.ietf.org/doc/html/rfc8058 https://datatracker.ietf.org/doc/html/rfc8058. Where the URL is in the headers as List-Unsubs

I was talking about https://datatracker.ietf.org/doc/html/rfc8058 https://datatracker.ietf.org/doc/html/rfc8058. Where the URL is in the headers as List-Unsubscribe: <URL> A 2 page overview is here: https://certified-senders.org/wp-content/uploads/2017/07/CSA_one-click_list-unsubscribe.pdf https://certified-senders.org/wp-content/uploads/2017/07/CSA...