>Emails demanding deletion of the memo contained “pixel trackers” that notified human resource managers when their messages had been read, recipients determined. This seems like the worst part (not that the rest is not bad), anyone has an idea of what this "pixel trackers" are and how they actually work?
Gmail sucks a bit because it always enables certain images in email and that means that google pixel trackers are really hard to block if you use google mail. If I were an employee, I’d switch to a non-google email client.
The privacy issue is problematic, but their functionality is also buggy. Untrained users will misinterpret them as they can get triggered by previews or other functions beyond just reading the message.