Yes, I understand, but I think it's a false premise that email can be secure at all. You shouldn't treat it as such and you should never send incriminating or sensitive information through email regardless of what promises are made about it being secure lest it is your own server. You can talk to people in much more convenient and actually secure and even anonymous ways and email does none of that so I don't know why it's expected to.

Email should, for 2-way communication, at best be used to establish actually secure connections elsewhere.

For all else, it should just be treated as an inbox that random people from the internet can dump stuff in for you to check out at your discretion.