I think he talking about e-mails to and from proton mail and other email providers are not really encrypted. Only mails between proton mail are encrypted.
That would be my guess.
That would be my guess.
The server still receives from other servers and from the client (if the email is not going to a proton account) the plain text, so nothing prevents them from making a copy.
They swiftly went on to win a court ruling that would prevent this specific situation from repeating. https://proton.me/blog/court-strengthens-email-privacy