PixelBlock is a Gmail extension that blocks people from tracking when you open their emails.
Used this for years, really loved it, I hope it is updated soon so it will work again with Chrome MV3.
As of 3rd March, the extension doesn't seem to be compatible with Chrome anymore and has been switched off in my browser.
Awesome, please update!
Tab Manager Plus
http://www.eff.org/
http://uglyemail.com/
http://disconnect.me/
http://www.gmass.co/
https://www.email-tracking-blocker.com/
https://gblock.app
https://digify.com/
https://trockerapp.github.io/
Thomas Rientjes
https://clearurls.xyz
https://simpl.fyi