How Email Tracking Works

On November 28, 2019
8min read
Stanislav Shymanskyi Product Manager @Mailtrap

Email tracking is hardly a new thing. It’s been commonly used by marketers and salespeople for at least 15 years. At this point, it’s safe to assume that most emails in your inbox are already tracked.

There’s no reason to panic, though. If you’re reading this article, you likely have a vital interest in tracking the performance of your messages. If you haven’t yet, it’s time to join the party with our comprehensive guide to email tracking.

What can you track?

Most commonly, email tracking is used to detect when an email is opened. The moment a recipient retrieves your message, you can be notified with appropriate notification. Other tools will simply mark a conversation as read.

The same way, if a conversation is opened multiple times, most tools will detect it each time. The caveat is that you often don’t precisely know who opens your messages as an email could be circulating between different people within the same company. More about how email open tracking works below.

The second most common thing that’s tracked are clicks on links included in the content. With the dedicated tools, you can determine which links resonate well with the recipients and which are not even pondered for a second.

Using tools such as Google Analytics, you can also know what precisely happens after a link is clicked and a recipient enters your website. Read more about it in our guide to tracking emails with Google Analytics.

One specific case for link tracking is with tracking unsubscribes. Nearly all platforms for mass email sending will force you to add an unsubscribe link to your messages. This is mainly due to regulations such as CAN-SPAM and GDPR that you need to comply with if you email people in the US and the EU, respectively. If users choose to opt-out of receiving future messages (or will simply mark you as a spammer), you will know that.

With link tracking, you can also determine the most important statistic – the conversion rate of your emails. Among other things that can be tracked are the user’s approximate location, device, and the email client they use. With all this data, you can improve your campaigns in many possible ways.

How email tracking works

All these things are possible with several different methods and tools utilizing them. Let’s see how email tracking works (and has worked in the past).

Read receipts

Read receipts have been quite a thing since the early days of email. The idea was that your email client, along with a message you tasked it with, would send a request to a recipient. This request would simply pop up in their client, informing them that you requested a read receipt and if they consent to sending one. They could, of course, decline it and very often they did.

The whole process could also be automated and users could agree to send such receipts by default. But few of them did, which made the tracking results far from accurate. 

Some clients never even supported read receipts and one could say they were right to do so – today, this method is very rarely used. Occasionally, it can be observed in corporations where a manager would email their colleagues and request a “written” confirmation that they have received a message. It should never be used in sales or marketing, though.

Tracking Pixels and Trackable Links

With the decline of read receipts, new approaches came to light and became no-brainers for any tracking tools.

Tracking Pixels are commonly used to detect when emails are opened. These are tiny, 1 by 1 pixel transparent images attached to emails. They’re invisible to recipients, don’t affect the way an email looks, and provide quite accurate results.

Each pixel is loaded with an individual tracking number which, when a message is loaded, marks it as read. Each new image that is opened will also be recorded and many tools will let you know precisely how many times a message was opened.

Trackable links are links modified with (often long) sequences of characters. Thousands of such individual links can still direct users to the very same web page. At the same time, they allow for accurately tracking their individual behaviors.

To give you an example, here’s a call-to-action from the latest Grammarly newsletter:

The link hidden behind it is as follows:

We’re not going to break this link down into pieces on this occasion. But it’s important to know that with the use of UTM parameters in this link, Grammarly can precisely know when their email is opened and by whom. It’s safe to assume any email sent with tools for mass mailing uses similar parameters. While they’re not pretty, they give tangible results to senders. 99.9% of readers won’t even see them.

Benefits of email tracking

You already know how tracking works, not let’s talk about why you should use it too! With the abundance of use cases, it should be a rather obvious choice.

Focus on prospective clients

If you’re in the business of sales, you certainly know the feeling. You carefully curate a list of prospective leads. For example, by exporting leads from the sales navigator, which is scraping LinkedIn and finding the best leads for your campaign. You build a great email, insert just enough personalization, and pick the right time to send using various email or lead generation tools. Yet, the results are disappointing at best.

A follow-up certainly won’t hurt. A second one might be of some help too. But can you do it forever? Unlikely.

With open tracking, you can quickly tell who actually opens your emails. You can also see those that do it repeatedly. If each new email results in 5 or 10 opens on their end, it is likely a message is being carefully analyzed by not one but a few team members. Give them a call or find another way to get in touch. You’re already on top of their heads and this can only help your cause.

The same way – if you can’t get someone to even open a number of your emails, you could be just wasting your time.

Improve your campaigns

Both marketers and salespeople can find a lot of insights from even a few emails sent. Tools for mass email delivery tend to aggregate tracking data in a fairly readable form. Right from the beginning, you can analyze your open and click through rates. You can also understand the audience better and know how many views your emails had on mobile or how many were based in the East Coast of the United States.

These and other details can be of invaluable help when trying to improve your campaign’s conversions. If you see that a long, detailed email doesn’t convert as well as you would expect, try sending a brief, straight-to-the-point e-mail next time. Maybe it will make things worse, who knows. But the more variations you try, the faster you’ll find a sweet spot.

With some tools, you can also A/B test your content. If you see a sudden spike in opens and/or clicks after implementing some change, you know you’re onto something.

Understand your clients better

Email tracking can (and often is!) used to build entire profiles of your prospects. We already mentioned things like location or software/hardware that they use to access emails. But opens and clicks can give a lot of information too.

With appropriate tools, you can quickly see which topics your prospect is keen about. They never read emails about new features but click every time you send some getting started tips? Chances are they’re a bit lost and would appreciate some help making their first steps. This really shows that you are thinking how best to serve them.

Maybe enterprise features get a lot of their attention, while the rest of your links generate close to zero clicks? Write this down and start the next conversation from the topic they care about most.

Things to keep in mind when tracking emails

All of this may sound exciting but one thing you need to note is that email tracking isn’t usually 100% accurate. Discrepancies can be observed mainly in open rates as different clients will treat tracking pixels differently.

Pixels, while invisible, are also images and are treated as such by all email clients. Some of them block images from being displayed by default. Some older clients are simply not capable of displaying HTML emails and will opt for plain text versions, stripping all attached images. In both of these cases, an email opened might not be recorded as a tracking pixel won’t be loaded.

Emails can also count as opened even if they weren’t viewed yet. This happens mostly for Outlook users. When new emails arrive, they’ll end up in Outlook’s preview pane. At this time, a tracking pixel can be loaded even if a recipient is looking completely elsewhere.

Finally, some users might be just blocking tracking pixels from loading in the first place in attempts to protect their privacy. While their use is not widespread, such plugins are easily available on the web and we’ll cover them briefly in the next paragraph.

By all means, don’t give up on email tracking because of these limitations. Just keep in mind that regardless of the software you use, you should always take the results with a (tiny) grain of salt.

How to prevent email open tracking

Hiding the information about when and if you open someone’s emails is very easy. It basically comes down to blocking images from displaying properly. This way, a tracking pixel won’t also be loaded by default, skewing someone’s data a little bit.

Here’s how to do it on popular email clients:


In Gmail, click on the Settings icon in the top-right corner of a window and pick “Settings” from the list. Scroll down and pick “Ask before displaying external images” from the “Images” field.

In Outlook, loading images should be disabled by default. To make sure this is the case, in Outlook pick Options -> Trust Center -> Trust Center Settings. The checkbox for “Don’t download pictures automatically in HTML email messages or RSS items” should be checked.

In macOS Mail app, follow the path Mail -> Preferences -> Viewing and uncheck “Load remote content in messages”

There’s also a number of plugins for Chrome and (some) for Firefox that can block images for you. Each will also notify you if trackers are detected in an email. Some popular choices are PixelBlock, Ugly Email or Trocker.


In the iOS Mail app, launch the iOS Settings app, choose Mail and disable “Load Remote Images”.

In the Android Gmail app, tap on the hamburger menu in the top-left and then choose Settings. Pick your account if you have a few, scroll down and under Images choose “Ask before displaying external messages”

There’s one thing you should keep in mind when using these tools or modifying your client settings. Blocking images from displaying by default will block not only tracking pixels but all other visuals too. Especially marketing materials such as newsletters and onboarding emails are often heavily stuffed with images. Some of these emails may lose on readability while others may become dysfunctional. 

Regardless, each of these clients offers a one-click feature for bringing back images to a single email. It’s not a seamless experience but this setup works pretty well for many.

Which tools should you use for tracking emails?

Since email tracking is so omnipresent, finding a tool with this feature won’t be challenging at all. In fact, good luck finding a tool for mass mailing without tracking features! 😉 

If you’re after transactional emails, you may find useful our summary of the best platforms for this case. Each of the tools mentioned there features extensive analytics to complement their sending capabilities.

If you have a limited budget, we also have a list of 15 free email trackers. These are the tools you typically implement with your email account. While Gmail or Outlook are great at creating and sending emails, they fall short when it comes to analytics. These email tracking tools solve this problem.

Maybe you didn’t realize it but free Google Analytics can be also used extensively to track emails. It’s particularly good at analyzing what happens after a click but can track opens quite accurately with a quick setup. We covered it all in our guide to tracking with Google Analytics, check it out.

Wrapping up

This wraps up our guide to email tracking but there’s a lot more to read about emails on our blog. We write about sending emails with particular frameworks and libraries. We talk about encryption and authentication methods and include tons of tips for improving your campaigns.

We also suggest how you can use Mailtrap to improve your emails. Mailtrap is a safe testing environment for staging and development. It captures your test emails and lets you analyze them before they’re sent to real users. There’s no longer a need to use production data for testing purposes. Curious how it works? Sign up for free today.

Article by Stanislav Shymanskyi Product Manager @Mailtrap