what are the main difference's with gmail? Is it that with gmail, you sign an agreement allowing them to read your email? that Proton mail the serveurs are in Switzerland? In Proton mail who has control of the private keys to sign a document? is it only you or Proton too? Who can recover them if they are lost. I have the impressions, that if you are willing to let gmail manage your keys it is just as encrypted or secret as gmail. Gmail will only make your emails readable if asked by law enforcement, but otherwise it is encrypted. same with Apple. In both cases they have the keys and you trust them. But Proton mail, if instructed to do so by law enforcement they will also make your data available. A case like that already occurred.