MailTrackerBlocker is a macOS Apple Mail plugin (i.e. mailbundle) to block read trackers disguised as "spy pixels".

Most commercial trackers can be reliably blocked through a blacklist of known URL patterns. Failing that, MailTrackerBlocker applies a generic regex filter for 1x1 images. Read more about how email pixel tracking works.

<img width="0" height="0" class="mailtrack-img" alt="" style="display:flex" src=
-"https://mailtrack.io/trace/mail/0eabccbe98c98e9b8e9a8b89eab89ce9ab89e8bc.png?u=1234567"
+"https://localhost/mail/0eabccbe98c98e9b8e9a8b89eab89ce9ab89e8bc.png?u=1234567"
>

Only tested on Apple Mail 13.4 on macOS 10.15 Catalina.

1. Download and install the latest .pkg from the releases page.
2. Open Mail, goto Preferences > General > Manage Plug-ins... > check "MailTrackerBlocker.mailbundle" > Apply and Restart Mail.
3. Tap on the ⓧ # button to find out what was blocked.

You can now reenable "load remote content in messages" if you had it disabled before using MailTrackerBlocker.

Delete /Library/Mail/Bundles/MailTrackerBlocker.mailbundle.

git clone https://github.com/apparition47/MailTrackerBlocker.git
cd MailTrackerBlocker
make

1. Give XCode Full Disk Access from System Preferences > Security & Privacy > Privacy > Full Disk Access and add XCode.
   • Need this because the plugin needs to be installed into the Mail Apps bundles at ~/Library/Mail/Bundles.
2. Open the Xcode project, hit build.

• GPGMail team for their work on Mail.app plugins
• @dhh for the spy pixel tracker blocking list used in HEY
• @bitmanic for the UI design