It's an uncomfortable truth that much of what we do online can be tracked in some fashion. We've all grown used to the idea that, unless you use a VPN, your web history can be followed easily by third parties. But one thing you might not realise is that emails can also be a way to monitor your activities.

Tracking pixels are now commonplace, and these let a sender know that you've opened an email they've sent, plus the time and date that you did so. They can even see if you've forwarded the message to anyone else.

So, how can you stop another part of your online privacy being taken away? Here's our quick guide to blocking email tracking.

What is a tracking pixel?

These are tiny bits of code that are usually hidden in images that are included in emails. When you open the email, they are triggered and send back the meta-data (it's open, here's when) to the sender.

This is similar to how you can get Read Receipts when you send messages to work colleagues, but in these cases the tracking pixels can be used to build up a picture of your activities, at least in regards to email. It's not life-threatening, but with so much of our lives now online, it's always good to control the information about you that people and companies can access.

Below we outline some ways to prevent tracking pixels from working, be aware though that this will only stop some from reporting on you. To safeguard your privacy fully, you'll need to look at browser plug-ins like MailTrackerBlocker (macOS) or Ugly Email (Chrome, Firefox), and we recommend using a VPN service like ExpressVPN or NordVPN to keep all of your online activities as secure as possible.

How to block tracking emails in Apple Mail on iPhone

In iOS 15 Apple introduced a new Mail Privacy Protection feature. The company states this "hides your IP address so senders can't link it to your other online activity or determine your location. It also prevents senders from seeing if you've opened the email they sent you".

It's usually turned on by default, but to manually enable the feature, do the following:

  1. Open Settings
  2. Go to Mail > Privacy Protection
  3. Enable Protect Mail Activity

How to block email tracking: Mail on iOS

For those using earlier versions of iOS, there are still some protections against email tracking. To use them, take the following steps:

  1. Open Settings
  2. Go to Mail
  3. In the Messages section, ensure Load Remote Images is turned off.

How to block tracking emails in Apple Mail on Mac

As with iOS 15, Apple has added the Mail Privacy Protection to macOS Monterey and it should be turned on by default. To check that the feature is up and running, here's the steps you need to follow:

  1. Open Mail
  2. Go to Mail > Preferences
  3. Select Privacy
  4. Enable Protect Mail Activity

How to block email tracking: Mail on macOS

In older versions of macOS, you can still have some protection against tracking emails by enabling the following feature:

  1. Open Mail
  2. Go to Mail > Preferences
  3. Select the Viewing tab
  4. Disable Load Remote content in messages

How to block tracking emails in Gmail on iOS

The Gmail app offers a protection feature against some tracking pixels. To enable this, here's the steps:

  1. Go to Gmail
  2. Open Settings
  3. Select your account name
  4. Tap Images
  5. Select Ask before displaying external images

How to block email tracking: Gmail on iOS  

How to block tracking emails in Gmail on Mac

Alongside the plugins we mentioned earlier, the web version of Gmail does offer some protection against email tracking. Here's how to turn the feature on:

  1. Go to Gmail
  2. Click the Settings (cog) icon and select Show All Settings
  3. In the General tab, find the Images section and select Ask before displaying external images
  4. Scroll down and select Save Changes

How to block tracking emails in Outlook on Mac

If you use the desktop app for Outlook on Mac, presumably with a Microsoft 365 subscription, then you can change the settings so that tracking pixels can have their effectiveness reduced.

To do so:

  1. Open Outlook
  2. Select File > Preferences > Reading
  3. In the Security section you'll see three options under Automatically download pictures from the internet
  4. Choose either Never or In messages from my contacts

How to block tracking emails in Yahoo on the web

If you're using the Yahoo web version, then you can minimise the way tracking pixels monitor your email.

  1. Go to Yahoo Mail
  2. Click on the Settings icon (cog-shape)
  3. Select More settings
  4. Select Viewing email
  5. Under Show images in messages, select Ask before showing external images

For more ways to protect your privacy and data, read our roundup of Mac viruses, malware and security flaws that you need to be aware of, and our best Mac antivirus recommendations, alongside our reviews of Avast Premium Security for Mac, Avira Free Security for Mac and Intego Mac Internet Security X9.