How to prevent your email from being tracked

All the unpleasant marketing emails that end up in your inbox do not just print a product. They also keep track of whether you opened the email, when you opened it and where you were at the time, using software like MailChimp to embed tracking software in the message.

How does it work? A single tracking pixel is embedded in the email, usually (but not always) hidden in an image or a link. When the email is opened, the code in the pixel sends the information back to the company’s server.

Attempts have been made to limit the amount of information that can be transmitted in this way. For example, since 2014, Google has been serving all images through its own proxy servers, which can hide your location for at least some tracking applications. And extensions like Ugly Email and PixelBlock have been developed to block trackers on Chrome and Firefox.

There is also a simple basic step you can take to avoid trackers: prevent your email from loading images automatically, as most of these pixels are hidden in the pictures. You will not be able to avoid all the trackers that can be hidden in your email this way, but you will stop many of them.

Here’s how to do it in the main computer and mobile email programs:

Disable Gmail AutoLoad:

• Click the rat icon in the upper right corner to access your settings and click “View All Settings.”
• On the “General” tab (the first one), scroll down to “Images”.
• Select “Ask before displaying external images.”
• Scroll down to the bottom of the page and click “Save Changes.”

Note that it will also disable the dynamic email feature of Gmail, which makes emails more interactive.

Disable image auto-loading in Microsoft Outlook (Office 365):

• Click “File”> “Options”.
• Select “Trust Center” in the “Outlook Options” window.
• Click the “Trust Center Settings” button.
• Check the boxes labeled “Do not automatically upload photos in standard HTML messages or RSS feeds” and “Do not upload photos in encrypted or signed HTML emails.” You can make a number of exceptions to the first item if you wish by checking the boxes below.

Disable image auto-loading in Apple Mail:

• Choose “Mail”> “Preferences.”
• Click on the “View” tab.
• Uncheck the “Load remote content in messages” checkbox.

Disable image auto-loading in Android Gmail:

• Tap on the three lines in the upper left corner.
• Scroll down to and select “Settings”.
• Tap the email account you want to work with.
• Scroll down to and select “Images”.
• Tap “Ask before displaying external images.”

Disable photo autouloading in iOS Gmail:

• Open Gmail for iOS, tap the hamburger menu at the top left, and scroll down to Settings.
• Tap the account you want to personalize, then tap ‘Images’.
• Switch from “Always display external images” to “Ask before displaying external images.”

Note that for those who want to do this on Gmail’s mobile client, it appears that for the time being, it will only work for personal accounts and not for businesses run by G Suite.

Disable image auto-loading in iOS Mail:

• Tap “Settings”> “Mail.”
• Find the “Messages” section and enable “Upload distance images”.

Another option is to use an email client like Thunderbird, which blocks remote images by default; the application allows you to download embedded content on an individual basis or not to send photos of contacts you trust hidden code in their images.

Update 3 July 2019, 15:47 ET: This article has been updated to include additional information about email clients.

Update 3 September 2019, 19:35 ET: This article has been updated to include instructions for disabling auto-uploading photos in Gmail for iOS.

Update 17 February 2021, 17:30 ET: Instructions for Microsoft Mail have been removed and some instructions have been updated.