Is Litmus Tracking Your Email? How to Block It

Most email tracking answers one question: did they open it. Litmus email tracking answers a harder one. It reports whether you glanced, skimmed or actually read, timed in two second blocks, and it does that from a domain, emltrk.com, that appears in no company's branding and tells you nothing about who is watching.

Key Takeaways

• emltrk.com is the tracking domain behind Litmus Email Analytics, a product sold to email marketers and design teams.
• Litmus's own Email Analytics API documentation lists per open fields covering email client, device type, operating system version, country, region, city and latitude and longitude coordinates.
• Read time is captured in 2 second increments from 0 to 18 seconds and above, and Litmus buckets the result as a glance under 2 seconds, a skim from 2 to 7 seconds, and a read at 8 seconds or more.
• The API also exposes print and forward events, including recipient details. Litmus has published rates of roughly one forward per 170 opens and one print per 313 opens.
• Litmus forbids senders from tracking people who have not opted in and accepts abuse reports at emltrk-abuse@litmus.com, but it publishes no opt out mechanism a recipient can use directly.

What Is emltrk.com and Why Is It in My Inbox?

emltrk.com is Litmus's email tracking domain, and Litmus maintains a public explainer page at litmus.com/emltrk precisely because people keep finding the domain and asking what it is.

Litmus is best known as an email testing platform. Marketers use it to preview how a campaign renders across dozens of clients before sending. Email Analytics is a separate product in the same suite, and it does something quite different: it measures what happens after the message lands.

To use it, a sender embeds a snippet of HTML that Litmus generates. That snippet contains a reference to emltrk.com. When your mail client renders the message and fetches the image, Litmus records the event and attributes it to you.

Because Email Analytics sits alongside a sender's normal platform rather than replacing it, a single message can carry two independent trackers: the one belonging to the sending platform and Litmus's own. A campaign sent through Salesforce Marketing Cloud, for example, can carry both that platform's pixel and an emltrk.com pixel. If you have read our breakdown of what Salesforce tracks in email, Litmus is the second layer stacked on top of it.

What Does Litmus Email Analytics Collect About You?

More per open than almost any other tracker in mainstream use. This is not inference from network captures. It is what the API returns to the sender.

• Email client. Named values such as Apple Mail, Gmail, Outlook and Apple iPhone, rather than a raw user agent string.
• Device type. Mobile, desktop, webmail, or image cache, which is the bucket used when a proxy fetched the image rather than a human.
• Operating system. Including version, so iOS 18 is distinguishable from iOS 26.
• Geolocation. Country, region and city, plus latitude and longitude.
• Read time. Measured in 2 second increments across a range from 0 to 18 seconds and above.
• Print and forward events, with recipient details attached.

Consider what that composite looks like when the same sender mails you weekly. Not a list of opens, but a behavioural record: this person reads on an iPhone on weekday mornings from one city, switches to a desktop client on Thursday afternoons from another, and spends 14 seconds on product mail and 2 seconds on newsletters.

How Does Litmus Measure How Long You Read?

By keeping the connection alive while the message is on screen, and counting.

A plain tracking pixel is a single request. It fires once, the server logs it, the transaction ends, and all the sender learns is that a fetch happened. Read time requires something more: the tracker has to know not only that the message was rendered but that it stayed rendered. Litmus's reporting exposes read duration in 2 second increments, which means the measurement continues while you have the message open and stops when you move on.

Litmus then buckets the result into three engagement tiers it uses throughout its own marketing material: a glance is under 2 seconds, a skim runs from 2 to 7 seconds, and a read is 8 seconds or more. Its public research on email attention spans is built from exactly this data, aggregated across its customers' campaigns.

There is a real asymmetry here worth naming. A sender who knows you opened the message knows one bit about you. A sender who knows you closed it after 1 second, three weeks running, knows something you never chose to tell them and would probably not say to their face.

Can Litmus Really See a Print or a Forward?

Litmus reports both, and it publishes rates for both: roughly one email forwarded for every 170 opened, and one printed for every 313 opened. Those numbers exist because the events are being counted.

Litmus does not publish the exact detection mechanism, so treat what follows as informed inference rather than documented fact. The tracking snippet is not a bare image tag; Litmus's API documentation notes it carries CSS rules targeting particular clients such as Outlook and Mozilla. CSS in email supports media queries, and a rule scoped to print media can request a different image than the rule that applies on screen. Two different image requests, two different events. Forward detection is simpler still: the pixel URL carries a unique recipient identifier, so the same identifier appearing from a new device, a new network and a new location is a strong signal that the message travelled.

The practical consequence does not depend on the mechanism. Forwarding a tracked email to a colleague can hand the original sender a data point about your colleague, who never received anything from them and never agreed to anything.

Can You Opt Out of Litmus Tracking?

Not directly, no. This is the honest answer and it is worth stating plainly.

Litmus's terms place the obligation on the sender. Senders are explicitly forbidden from using Email Analytics on subscribers who have not opted in, and are required to provide a working unsubscribe mechanism for their mailing list. Recipients who believe they were tracked without opting in can forward the message to emltrk-abuse@litmus.com for investigation.

Notice the gap. Unsubscribing removes you from the sender's list. It does not switch off Litmus tracking on the mail you continue to receive from everyone else, and there is no Litmus level preference you can set once and be done with. The abuse address is a complaints channel, not a control.

Which means the only reliable control sits on your side of the connection.

How Do You Block Litmus Email Tracking in Gmail?

Four approaches, with the tradeoffs stated honestly.

Stop images loading automatically. In Gmail, open Settings, See all settings, and under Images choose "Ask before displaying external images". Nothing from emltrk.com loads until you approve it, which also kills read time measurement outright since the connection never opens. The cost is that every legitimate image in every email breaks too.

Apple Mail Privacy Protection. If you read mail in Apple Mail, MPP proxies image loads and hides your IP address, which is why Litmus reports an "image cache" device type at all. It is a partial defence: it prefetches whether or not you opened the message, and it does not apply to Gmail in a browser, where most people actually read mail.

Inspect the source before you trust a message. In Gmail on desktop, use the three dot menu and choose Show original, then search the raw source for emltrk.com. Our walkthrough on detecting tracking pixels in Gmail covers the full process. Useful for auditing a specific sender; impractical as a daily habit.

Use a blocker extension. Ugly Email flags tracked messages with an eye icon in the inbox list before you open them. PixelBlock blocks open pixels but leaves rewritten links alone. Trocker works across several webmail providers and shows you where the pixel sits. Our side by side comparison of Ugly Email, PixelBlock and Trocker lays out where each one stops short.

Gblock belongs in that last category. It runs inside Gmail rather than asking you to switch clients, keeps an auto updating blocklist so newly identified tracker domains are covered without you maintaining anything, and strips tracking links as well as pixels. What it will not promise: no blocker catches every tracker, and a sender who moves tracking onto a custom subdomain evades domain matching by design. An IEEE analysis of 44,000 emails found pixel blockers are evaded more easily than most users assume. Domain blocking is a strong filter, not a guarantee.

Is Litmus Tracking Legal?

It depends entirely on where you are, and Europe has moved decisively.

The EDPB's Guidelines 2/2023 on the technical scope of Article 5(3) of the ePrivacy Directive concluded that a tracking pixel instructs the recipient's device to send information to a remote server, which brings it inside the consent requirement. That analysis turns on the technical act, not on whether you subscribed. National regulators have followed: France's CNIL and Italy's Garante have both issued email pixel guidance, and we covered the CNIL recommendation and its deadline when it landed.

In the United States there is no equivalent federal rule, but there is litigation. Class actions arguing that an unconsented email pixel amounts to interception under state wiretap statutes have been filed in volume, and our coverage of the CIPA email pixel wave tracks where the courts have landed so far.

Litmus's own rules are stricter than the law in most US states, and a sender who follows them is tracking only people who opted in. The problem is that you cannot tell from your inbox which senders follow them. If you want to know what is actually watching you across all your mail, our guide to the Gmail read receipt tools in common use is the place to start. Retail mail is its own case: we looked at what Attentive reports back to the brands that send it, and the answer is much thinner than Litmus.