Block Mail Trackers

July 5, 2019

The recent dust-up over the Superhuman mail application tracking when recipients open email, down to the level of the exact timestamp every time they opened it and their location, brings to light an important privacy issue. When/where/if you read an email someone sent you is private. Email services that attempt to track that are intrusive.

There are a few different ways you can reduce mail tracker spying…

Or, more blunt but highly effective, block known mail tracker domains at the network level. Little Snitch on a Mac is a great tool for this…

Little Snitch

Little Snitch is a network connection filter. Allowing you to allow or deny network access on your Mac.

Download and install Little Snitch 4. This installs a kernel extension, so be sure to follow the instructions to allow the extension, and restart your Mac as indicated.


I compiled a Little Snitch block list based on articles and extensions.

Set up the rules yourself or download and import my list, or subscribe to it.