I was using secure, private, paid email long before protonmail became the in thing. I have also heard some Dommes complain about the functionality of protonmail, but that was in the beginning. Hopefully they have worked that out. I do agree that all Dommes should be using some form of secure email - however, it's only secure on one end. If the client uses gmail or the like there is no security regardless of what email the Dommes uses.