If you care about such, you need to encrypt the content of your email. Then it will be like a letter instead of a postcard. Alexander the Geek will still get t

If you care about such, you need to encrypt the content of your email. Then it will be like a letter instead of a postcard. Alexander the Geek will still get to add your metadata to his haystack, but, FWIW, the body of your email will remain in a long, long decryption work queue.