I would assume it would have the same effect as with end-to-end encryption mails, where you just have unencrypted data when you are communicating with people th

I would assume it would have the same effect as with end-to-end encryption mails, where you just have unencrypted data when you are communicating with people that don't support this. Such as is the case with https://protonmail.ch/ https://protonmail.ch/