You've got that backward. If google fires off a request when you open the email, the companies can track whether you opened the email. If google fires off a re

You've got that backward. If google fires off a request when you open the email, the companies can track whether you opened the email. If google fires off a request when they get the email, the company has no way to track if you opened their email. If google fires off requests to all emails they receive to @gmail.com then the marketers won't even know if it's active @gmail.com account, they'll just know that *@gmail.com is received, which isn't information, it's an easy assumption.