Let's face it. An email is a post card sent across a globally accessible media. So, to think you have "Private" email is just not facing reality. It's like sending your post card blown up on a flat bed trailer just faster.
Now you get to "But it's https (encrypted)(Google) and that's where the problem lies.
The company has sucked you in with security that it does not provide. It's not the security from various local malcontents, it's from the government.
Obviously to reduce the governments overhead decrypting every message they can sniff off the line. Companies are charged with feeding them the decrypted stream ... and that is the problem.