I am not suggesting that email clients should entirely depend on OpenPGP email inherent resistance to oracle attacks, only pointing out that it exists. Presumab

I am not suggesting that email clients should entirely depend on OpenPGP email inherent resistance to oracle attacks, only pointing out that it exists. Presumably the Enigma operators were not putting their decrypted messages in envelopes before sending them off to their enemies. Efail was primarily a straight up plain text leak. Plain text attacks come in distinct categories. The block ciphers used in OpenPGP are generally considered to be immune to the sort of plain text attacks used against Enigma.