I think in general treating email any other way than "everyone will eventually read your mail" makes no sense. Email communication, from forwarding to how people archive, to copy-pasting provides no security and is so brittle, just assume anything you write in an email is for public consumption. Reminds me of a post from a few years ago about encrypted mail as a security LARP (https://www.latacora.com/blog/2020/02/19/stop-using-encrypte...)
If you want secure messaging that nobody else will snoop on use an application dedicated to.. secure messaging. It's never what email was for and it's not how it's being used.
If you want secure messaging that nobody else will snoop on use an application dedicated to.. secure messaging. It's never what email was for and it's not how it's being used.