I am looking for a browser extension / userscript that can warn me when an e-mail I open in the Gmail web interface is being tracked by Streak, which is a Gmail plugin that enables someone sending me email to tell whether I opened an email or not, without my knowledge.
Preferably, it would work with Google Chrome and block the tracking (i.e. makes it possible for the sender to see that I opened his email), ideally without preventing me from using Streak, as it would if I was using AdBlock to ban blocked 173.194.70.141, mailfoogae.appspot.com following this forum thread.