<img height="1" width="1" style="display:none" src="https://www.facebook.com/tr?id=1822615684631785&amp;ev=PageView&amp;noscript=1"/>

Mailtrack just did something brilliant

As the developer of two Chrome extensions, GMass and Wordzen, I’m always on the lookout for what other Chrome extension developers are doing. Mailtrack is a popular Chrome extension for Gmail that tracks individually sent emails. GMass tracks sent emails too, but it’s mostly used for batch email campaigns, although you can use GMass’s tracking features on individually sent emails as well. But I digress…in this post, I’ll focus on Mailtrack’s brilliance.

Mailtrack and Chrome extensions

MailTrack is one of the most popular Gmail Chrome extensions on Earth, with nearly 900,000 users, according to the Chrome Web Store. I admit, I’m envious of their growth and would love to see GMass have that many users.

One of the limitations of Chrome extensions has always been that they only work on the desktop, and not on mobile. GMass only works on the desktop, not on mobile. Wordzen only works on the desktop, not on mobile. Same with Mailtrack.

So when I saw their announcement that they could now show you the checkmarks indicating whether an email has been opened in the Gmail mobile app, my immediate reaction was, “No way, impossible!”

I had to see for myself. First, I turned ON the mobile option on the Mailtrack Settings page.

The checkmarks on the iPhone Gmail app

I sent a tracked email using Mailtrack to [email protected] from my desktop, and then looked at it in the Sent folder on both the desktop and iPhone.

Sure enough, the famous Mailtrack checkmarks were there.

Mailtrack shows the checkmarks in the Gmail app on both iPhone and Android by applying Labels that are named ✔ and ✔✔.

But how on Earth did they do this?

Did they hack the Gmail app? Did they develop a Gmail Add-on, which is a new way of developing functionality for the Gmail mobile app that was introduced just six months ago? Maybe, but that sill wouldn’t make sense because Gmail Add-ons currently only work on Android, not on iOS.

A closer look, and I discovered the brilliance of the Mailtrack developers.

The answer? Labels.

They creatively apply Gmail Labels to show whether an email has been opened. Looking at my account, I found two new Labels had been created, the first with one checkmark and another with two checkmarks.

Mailtrack creates two new Labels in your account, a single-checkmark Label and a double-checkmark Label.

When an email is sent, Mailtrack programatically applies the ✔ Label. When an email is opened by its recipient, Mailtrack removes the ✔ Label and applies the ✔✔ Label. Since the mobile Gmail app  always shows the Labels that are applied to a message, you see checkmarks next to the message! Just brilliant.

But wait, if they’re applying these Labels now, won’t they also show up in the desktop UI?

No, they made it so that the Chrome extension hides the checkmark Labels when applied to a message, so that the user instead sees the more aesthetically pleasing checkmarks in the message list view.

The more aesthetically pleasing checkmarks look like this and show up when viewing a list of messages.

In the Gmail web interface, the Mailtrack Chrome extension shows the checkmarks in an aesthetically pleasing way, without the use of Labels.

Hiding the Labels in the web version of Gmail

In the example below, you can see the Sent Mail with the “✔✔” Label applied in addition to another Label, “Client Projects”, that I manually applied myself. But only the Client Projects Label shows next to the Subject. Where is the “✔✔” Label?

The Mailtrack Chrome extension is preventing its own checkmark Labels from displaying.

The Mailtrack Chrome extension is hiding it.

We can prove this by removing the Mailtrack extension and reloading Gmail.

Voila, now you see the checkmark Labels applied to a Sent Mail.

The Mailtrack Chrome extension hides its own Labels in the Gmail web interface. Deleting the Mailtrack Chrome extension reveals the checkmark Labels.

Since the UI of the mobile app can’t be altered by a Chrome extension or anything else, the checkmark Labels do show on mobile, which is exactly what they want.


The Chrome extension alters the UI to show the more aesthetically pleasing checkmarks while hiding the checkmark Labels. The native Gmail mobile app always shows the checkmark Labels and nothing else, since developers don’t have the ability to change the UI of the Gmail mobile app.

This is the most brilliant use of Gmail Labels that I’ve ever seen.

See why 99% of users say they’ve had their best deliverability ever with GMass

Email marketing, cold email, and mail merge all in one tool — that works inside Gmail


Download Chrome extension - 30 second install!
No credit card required
Love what you're reading? Get the latest email strategy and tips & stay in touch.

  1. Ajay, thanks for getting Mailtrack on our radar. Is this a functionality Gmass is able to implement or setup for its users/customers?

    1. Hi Sherman,

      It’s just going to take some time because we have a long list of things on our roadmap right now. It would be a nice addition and we’re hoping it’s something we could add on sooner than later.

  2. I have three questions. I use Outlook to manage my emails and my email address is Gmail.
    1. Will Mailtrack work for me?
    2. Is there a mail merge feature with Mailtrack?
    3. I work for a small nonprofit – do you have any discount program for nonprofits?

  3. Hello,
    I use Outlook to manage my emails and I have a Gmail address. Will Mailtracker work for me?
    Also, I work for a small nonprofit do you give discounts to nonprofits that are working to make the world safer?

    1. Hi Kay,

      MailTracker will only work on Gmail using Chrome.

      Yes, we offer a 15% discount for non-profits and educational institutions with domains ending in .org or .edu. which will automatically be applied to your invoice upon checkout.

  4. You said that you sent the email from your desktop. If you sent it from your mobile, using the Gmail App, would tracking still be available? Or, only from the desktop?

  5. Honestly I don’t see any brilliance here. In programming it is called bypassing the parameters,which is quite unique.

    1. Hi Taufan,

      Yes, you can use Mailtrack and GMass together. Please contact our support team so that we can assist you in troubleshooting. Please see gmass.co/g/support.

      1. Hello,

        As per your answer that Mailtrack and GMass can work together, I would like to inquire how so. I just subscribed to a quarterly plan on Mailtrack prior to me discovering GMass’ existence. I love how GMass is taking a different approach to make email tracking more undetectable, so I would have probably preferred going with you guys. Now that I am already locked in with Mailtrack for at least the next 3 months, how could I use GMass? I do not mass-mail and only require to monitor emails sent to certain entities regarding legal matters, so I fly solo in GMail.


  6. Ajay – brilliant article.. I was wondering whether mailtrack does something special on email headers?
    When I send it and look at original source, it shows data/base64
    But on recipient side it looks like an actual image url..
    Do u know how the sender content and receiver content for mailtrack is different?
    There’s a stackoverflow post at https://stackoverflow.com/questions/65538542/how-do-mail-trackers-make-the-original-email-different-for-the-recipient-and-the but no correct response

Leave a Reply

Your email address will not be published. Required fields are marked *

Transform your Gmail account into an email marketing powerhouse

GMass is easy to learn and easy to use — but brings unbelievable email power into Gmail

Try GMass for free Then check out the quickstart guide to send your first mail merge email in minutes!


Share This