Email Privacy Protector is described as 'Anytime you open your emails, people could be tracking when you do it, and which links you click on. Protect your email privacy' and is an app in the Security & Privacy category. There are four alternatives to Email Privacy Protector for a variety of platforms, including Mac, Windows, Google Chrome, Linux and Apple Mail. The best alternative is MailTrackerBlocker, which is both free and Open Source. Other great apps like Email Privacy Protector are Ugly Email (Free, Open Source), Trocker (Free, Open Source) and PixelBlock (Free).
MailTrackerBlocker is a plugin for the default Mail app built-in to macOS. When you view your email a 🛑 # button will appear to indicate the number of services blocked. Tap on the button to show which services have been blocked.