It would be very useful to implement your proton email client so one could add also other email clients in (google, exchange,...). Really like the mail app, and would like to use it as my daily driver, but since I have also work emails I need to check regulary and do not want to have two email clients installed, I just use outlook/gmail. Sure I can add my proton account to outlook, but that kinda looses the whole idea on having a secure email.