Gmail users, be aware: “Gmail has 1.4 billion email users. Every one of those users has agreed to terms of service that give third parties permission to read their email. And, of course that’s just what they do.”
Admittedly, this summary is slightly alarmist (but only slightly), as you do need to have given permission by signing up for an offer or service that performs this sort of activity. But that’s not exactly an unlikely scenario for many people.
Just one more reason why I’ve done my best to move away from Gmail whenever possible. While I still have a Gmail account, I moved to Apple’s mail services a few years back, and the Gmail account is little more than a spam and “I need to either unsubscribe or update my email settings” catcher at this point. I’d have nuked it entirely if I could figure out how to transfer my various Google accounts to a different email (which they don’t seem to be interested in letting you do, or at least telling you how to do so).
Yes, Apple’s another Big Company, and there are those who distrust them as well. But I trust Apple’s privacy stance much, much more than I do Google’s. It’s been a long time since I put much stock in Google’s late, lamented, “Don’t be evil” philosophy.