I discovered way too late there's a block option in #protonmail if you click on the sender address which is not available as a button or in the message menu (but after you select it unblock shows up as a button)
protonmail
Buried in Proton's AI announcement today is a pretty shocking detail about their service 👀
Because of legal uncertainty around Swiss government proposals to introduce mass surveillance — proposals that have been outlawed in the EU — Proton is moving most of its physical infrastructure out of Switzerland. Lumo will be the first product to move.