David J. is a huge fan of music superstar Jay-Z. Over a two year period David sent the music mogul at least 262 emails, but never received a reply. But David knew Jay-Z (or someone who works for him) opened the emails.

According to David, “Jay has opened every single one of my emails, even re-opening them to re-read. He has clicked on links and had emails open for as long as 20 minutes.”

Now, make no mistake, David isn’t a private investigator or even a cyber-hacker.

He gathered this information using software called ReadNotify. The software embeds a small, unique, invisible image in every e-mail he sends.

Whenever a recipient opens an e-mail, this embedded image loads from ReadNotify’s servers. The servers record the time of the view, its duration and the location of the viewing.

ReadNotify then gives the sender a read receipt, confirming that the message was seen. Using this software, David was able to track the e-mails he sent to Jay-Z. He knew the precise time his emails were opened – and how long they stayed open…

And he also knew where the emails were opened, including detailed information such as: The exact IP address, and specific location of whoever opened the e-mails.

With that information, he compared the locations of the email opens to where Jay-Z was appearing, or holding a concert. For example, two days before Jay-Z scheduled a show with U2 in New Zealand, someone opened one of David’s emails near Auckland.

Another email, sent while Jay-Z was vacationing in France, was opened from an iPhone in Paris. Of course, it’s possible Jay-Z’s assistant opened the emails…

But either way, this shows how easy it is to track someone through email. Now, you may be wondering what trackers can do with this information…

Well, like the story about Jay-Z, someone could use e-mail tracking to learn about where you are. For instance, let’s say you are on vacation in Europe and your neighbor who you don’t trust sends you an e-mail.

By using email tracking, they can be certain you’re out of town. Or let’s say a co-worker is sharing private company e-mails. An e-mail tracker can prove the co-worker is forwarding private e-mails to another party.

How big of a problem is email tracking? About 269 billion emails are sent and received daily. That’s roughly 35 emails for every person on the planet, every day. And over 40 percent of those daily emails are being tracked.

In fact, researchers from Princeton University analyzed about 1,000 specific advertising e-mails. They found that 70% of the advertising e-mails contained ad trackers. And 20 percent of all “conversational” emails are tracked.

That means: one out of every five emails you get from your friends or family are tracked by somebody. But there are a few simple things you can do to protect yourself from being tracked via e-mail.

Anti-tracking extensions. Most email-tracking programs use pixel tracking.

It works like this:

The sender adds an invisible, one pixel image to the end of the email. When the email opens, the pixel loads, and the sender uses it to track the email.

There are many browser extensions available that will block the tracking pixels. They also alert you to emails that contain trackers, so you can block them.

Here are a few of the most popular extensions that block pixel tracking:

PixelBlock… Trocker… and Ugly E-mail.

Turn on image-blocking in e-mail settings. A quick and easy way to stop email tracking is to block images from displaying by default in your e-mails.

Email providers allow you to block images from downloading, by changing your email settings. But remember, you will be blocking ALL images.

And if you use an e-mail app on your smartphone or tablet to check e-mail, you’ll need to enable this setting in that email app as well. Again, you can do this in the app’s settings.

Use a VPN on every device. I cannot stress enough how critical a virtual private network (VPN) is for security. These days you can get VPN’s for free or for a small monthly fee depending on the provider.

Personally, I use a VPN called TunnelBear, which has different prices depending on the features you want. A VPN won’t reveal your actual location. So even if someone is tracking your e-mails they won’t ever know your physical location.

The reality is e-mail has evolved from simple text. They now use all kinds of fonts, styles, and embedded images. In fact, e-mails are now like web pages in their design. Because of this, they can pose a similar threat to your cyber- security.

But by using these simple tips you can prevent someone from tracking you using email.