According to Spam Laws, 14 billion spam emails are sent daily, accounting for 45% of all email. 40% of emails contain a tracking pixels (aka tracker images, web beacons, web bugs, tracking bugs, web tags, page tags, pixel tags, 1 x 1 GIFs, and clear GIFs). A journalist who used a tracking tool to research email tracking believes Apple CEO Tim Cook read his email using a Windows computer.

Reading or Previewing an Email Can Harm You

Just opening - or previewing - an email can display tracking images that can be used to collect all kinds of information about recipients, including:

• when, where, with which email client, using which email provider and on what device the email was opened
• how long the message was opened
• how many times the message was reopened
• whether or not you clicked any links within the message
• what type of device you used to open the email
• how many times and to whom the message was forwarded

Hackers, spammers, scammers can use this information to target you for phishing or other harmful activities.

A Simple Solution: Don't auto-display images

The simple solution is to disable the display of remote images or remote content.  Even better, some providers can block all remote content.  A few offer the ability to block embedded images, which can be used to transmit malware when displayed.

Privacy focused email providers like ProtonMail and Tutanota block external images by default.  Tutanota doesn't even allow external images to be displayed by default, but it allows you to identify trusted senders so future emails can display images without prompting.

Superhuman offers a service for tracking the emails you send, and it doesn't allow its customers to block images on the email they receive.

More Help is On the Way

Privacy and security focused providers are developing new ways to eliminate - or eliminate the benefit of - tracking pixels.  Apple is deploying a proxy server to disguise the recipient. Privacy-focused search engine provider DuckDuckGo is testing a proxy email service that removes trackers before forwarding them to recipients.

For now, the most effective way to protect yourself is to simply not display images in email.  And watch out for similar techniques in texts and instant messages, too.

Resources

How to Stop Images from Automatically Downloading in Emails