There's been a lot of talk recently about email tracking. What used to be a business tool, or a technique used by a niche of power users, is now common and even enforced in a new wave of email clients.

Emails are generally tracked via an image called "pixel-beacon", or "tracking pixel", which is usually just 1px wide and invisible. As soon as you open an email, this image is downloaded by your email client, which silently sends some personal information – like your general location and the device you're using – to the sender.

We don't think there's something inherently wrong with this technique, but there should be more awareness around it and users should be fully aware of email tracking.

A recent example of how email tracking can be forced on users came from Superhuman, a cool startup making an invite-only and expensive email client focused on productivity and good design.

Mike Davidson explains why email tracking like the one Superhuman does can be harmful:

It is disappointing then that one of the most hyped new email clients, Superhuman, has decided to embed hidden tracking pixels inside of the emails its customers send out. Superhuman calls this feature “Read Receipts” and turns it on by default for its customers, without the consent of its recipients. [...] If you send an email using Superhuman (no matter what email client you use) [...] this is what you see: a log of every time someone has opened your email and what location they opened it from. That’s right. A running log of every single time you have opened my email, including your location when you opened it. Before we continue, ask yourself if you expect this information to be collected on you and relayed back to your parent, your child, your spouse, your co-worker, a salesperson, an ex, a random stranger, or a stalker every time you read an email.

How to know when the sender is tracking you

To fight this trend, we decided to go in the opposite direction and implement a new feature in our Mac email client Boxy Suite.

Starting today, you'll be able to detect email tracking. Here's how it looks:

Boxy Suite will search for a "tracking pixel" inside the email body, and match its URL to a little database to find out what tool is used to track the email. We love the idea of empowering our users and protect their privacy, so this update brings us closer to this goal.

If you want to try this, download Boxy Suite now (there's a free trial with credit card, which you can cancel anytime).

How to stop the email trackers

Gmail already uses a proxy for images, so email trackers don't know when and how you're reading an email, but they still know that you've opened it.

To stop this, you can disable external images by default in Gmail, and therefore Boxy Suite, following these instructions: just click on the gear icon in the upper right-hand corner and select Settings, then under the General tab, find the Images section. Tick the Ask before displaying external images bubble.

Even if you disable external images, Boxy Suite will tell you when an email has a tracking pixel anyway, so you'll be able to decide if you want to load images or not based on that.