ProtonMail introduces a new email tracker blocking system

ProtonMail has introduced an enhanced email tracking protection system for its web-based email solution that prevents senders from being tracked by recipients who open their messages.

ProtonMail is an end-to-end encrypted email service based in Switzerland and uses a client-side encryption approach to maintain user privacy and protect their communications from snooping intermediaries.

40% of all emails have trackers

According to a 2017 study, almost half of all emails sent and received feature trackers that beam information back to the sender.

The information includes the time a recipient opened an email, how many times it was revisited, what device was reached, and the recipient's IP address.

How email trackers work
Source: ProtonMail

These trackers are practically invisible since they are just tiny pixels in an image embedded on the email body, and they log data about the user activity every time the message is opened.

Email trackers are predominantly used for targeted advertising but can also be used for de-anonymization, to expose the recipient's information to third parties, or simply to monitor when someone has read your email.

The collection of this data occurs without the user's consent, but these systems are hard to regulate, so the best approach is to block them.

Blocking trackers for all users

ProtonMail will now start blocking email trackers by default on all accounts, including free (non-paying) users.

The webmail service will block the identified as risky pixels and hide the user's IP address so that their location remains concealed.

Pop up informing the user about blocked trackers
Source: ProtonMail

Whenever a tracker is blocked, the user will get a relevant notification with a clickable icon that holds more information on the detected trackers.

As the company explains, this new system won't affect subscribing to newsletters or registering for online services.

ProtonMail users can check if this privacy feature is enabled by going to Settings > Email Privacy and confirming if the Block email tracking setting is toggled on, as shown below.

Block Email Tracking setting in ProtonMail

Other ways to protect yourself

If you're not using ProtonMail, but you still want to protect yourself from email trackers, try disabling image/resource loading on your email client.

This option is available on Thunderbird, Outlook, Gmail, and Apple Mail, and should be enough to block most trackers from loading.

You can also turn off HTML email entirely and read your messages in plain text form for additional security. However, this measure is not recommended for a pleasing user experience but could help in cases where privacy protection is critical.