Spark Mail Read Receipts: Is Spark Tracking Your Email?

Spark read receipts are real, and you do not have to use Spark to be on the receiving end of them. When someone sends you an email from Readdle's Spark Mail app with Read Statuses switched on, the message carries an invisible image. Open it in Gmail, and a small eye icon on the sender's screen changes state. Nothing on your side asks permission first. This is Spark email tracking, and it works on your inbox whether or not you have ever heard of the app. (Not to be confused with SparkPost, the unrelated bulk email platform we covered in Is SparkPost Tracking Your Email?.)

Key Takeaways

• Spark Mail's Read Statuses feature, available only on the Pro and Enterprise plans, uses tracking pixels to tell the sender if and when you opened their email.
• Readdle removed an earlier read receipt feature from new Spark installs in version 1.0.1 on July 9, 2015, saying it was pulled "due to mixed reviews."
• The sender sees an eye icon that turns blue once every recipient has opened the message, plus a list of who opened it, most recent reader first.
• Readdle says Read Statuses do not process recipients' IP addresses, device metadata or location, but its tracking host is undocumented and the claim cannot be independently checked.
• Gmail's own help page admits "senders may know whether you've opened an email that has an image," so the reliable fix is stopping the pixel from loading.

Does Spark Mail Have Read Receipts?

Yes. Spark calls them Read Statuses, and according to Readdle's help center, the feature "is available exclusively in the Spark Pro plan, as it is designed primarily for business use." The same page is blunt about the mechanism: "Read Statuses work using invisible images called tracking pixels added to an email. When the recipient opens the email, their email client loads the image from the server, letting you know it was opened."

That is not a traditional read receipt. A classic receipt is a header that asks your mail client for permission to confirm the open, and you can say no. A tracking pixel never asks. Our explainer on how Gmail read receipts work covers the difference in detail, but the short version is that the pixel reports the open whether you consent or not. Polymail goes further, logging clicks and attachment downloads through share.polymail.io, as we detail in our Polymail read receipts breakdown.

On the Spark pricing page, Read Statuses sits in the Pro tier, which Readdle pitches "For professionals and client-facing teams who want to drive growth," alongside a HubSpot integration. Enterprise includes it too. Free and Plus users cannot send tracked mail, so the Spark senders who can track you are the paying business accounts the tier is built for. Desktop clients sell the same thing: Mailbird's email tracking reports who opened a message and when, with no prompt for the recipient to refuse.

One correction to a common assumption. Spark's help center does not describe a per message tracking switch. Senders enable Read Statuses once, under Settings, then Composer on Mac and Windows or Settings, then Read Statuses on iPhone and Android, and pick whether to be notified about "All recipients" or none. The notification choice changes what the sender is alerted to, not whether the pixel is sent. Readdle does not document the default state of the toggle.

Spark Already Tried This Once, in 2015

Spark launched on iOS in May 2015, according to Wikipedia's entry on Readdle. It shipped with read receipts. About six weeks later, on July 9, 2015, iDownloadBlog reported that Spark 1.0.1 carried this changelog line: "We removed Read Receipts functionality for new Spark installations due to mixed reviews. Hopefully, we will bring it back someday." Existing users kept the feature. The same update added a setting to disable "Load remote images" to protect privacy.

Readdle did bring it back, with two changes. The feature now has a different name, and it now sits behind the most expensive self serve plan. The pixel itself is the same idea. Superhuman went through its own reckoning when Superhuman's read statuses drew criticism in 2019. Spark had that argument with its users four years earlier.

What Does a Spark Sender See When You Open Their Email?

A Spark sender sees an eye icon next to the sent message with three states, per Readdle's documentation:

• Eye with a strikethrough: nobody has opened the email yet.
• Grey eye: some of the recipients have opened it.
• Blue eye: every recipient has opened it.

Tapping the icon shows "the list of recipients who have already seen the email, starting from the last one to read the message at the top." Readdle's Read Statuses feature page adds that it "only shows the approximate time an email was opened and who opened the email." If the sender picked "All recipients" for notifications, they also get an alert as you open it.

Notice the phrase "who opened." On a message sent to five people, Spark can tell the sender which of the five read it. That only works if each recipient's copy carries its own distinguishable image address. This is our inference, since Readdle does not publish the mechanism, but it means the pixel in your copy is tied to you, not to the thread.

What Readdle Says It Doesn't Collect, and What Nobody Can Verify

Readdle's feature page states that Spark does not process recipients' device metadata, IP addresses or location information. That is a stronger promise than most sales trackers make, and we have no evidence it is false. We also have no way to confirm it. Any pixel request reaches a server with an IP address and a user agent attached; whether that server logs them is a policy question, not a technical one.

Here is what we could and could not establish as of September 2026:

• Pixel host: not documented. Neither the help center, the feature page, nor the privacy policy names the domain the tracking image loads from. Observing it requires receiving a tracked email from a paying Spark Pro account, which we did not do, so we are not naming one.
• Retention: documented. The Spark privacy policy dated September 10, 2026 lists "Read Statuses" with a storage term of "Until deletion of the Spark account." Your open events live as long as the sender's account does, and you have no account to delete.
• Server side processing: partly documented. The same policy says email data is mainly processed on the device, but "if you use such features as shared emails, shared drafts, emails to send later, etc., we will process your data on our servers." Send Later emails are kept "Until the email is sent," and "Recent emails" are kept "For four (4) hours." Login credentials "are stored as a token, and we cannot retrieve or access them."
• Location: US and EEA. The policy says personal data is stored on US servers participating in the Data Privacy Framework and on EEA servers, with daily backups via Google Cloud SQL.

None of this makes Spark unusual among modern email apps. It does mean a record of when you read someone's message sits on Readdle's infrastructure, governed by a policy you never agreed to.

The Irony: Spark Blocks the Pixels It Sells

Scroll further down the same Read Statuses help page and Readdle switches sides. Under "How to block tracking pixels in Spark?" it says: "Spark blocks 1x1 tracking pixels by default. That doesn't cover the whole range of tracking pixels, but already offers decent protection." For full coverage it recommends turning off remote images entirely.

Most coverage of read tracking treats vendors as either trackers or blockers. Spark is both, on one help page. Edison Mail flips the pattern: it never reports your opens to senders, but funds itself with data pulled from your receipts, as our Edison Mail privacy breakdown explains. The practical consequence is lopsided. If you read mail in Spark, you get some protection from other people's pixels. If you read mail in Gmail, as most people do, you get none of Spark's default blocking, and a Spark Pro sender's pixel loads like any other image. Readdle's own line, "doesn't cover the whole range," is also the most honest description of static pixel blocking anywhere in the industry, including for the tools listed below.

Can You Tell If a Spark Email Is Tracking You in Gmail?

Not from Gmail's interface. Spark does not create a new address; a Spark user sends through their existing email account, so the email arrives looking like any other message, with no banner or label. Google's Gmail image help page says its image scanning means "Senders can't use image loading to get information about your computer or location," then adds: "Sometimes, senders may know whether you've opened an email that has an image." Gmail hides where you are. It does not hide that you opened the message.

You can inspect a suspicious email yourself. In Gmail on the web, open the message, click the three dot menu, and choose "Show original." Search the raw HTML for image tags pointing at unfamiliar domains, especially tiny ones with long unique strings in the path. That will not prove a pixel belongs to Spark, since the host is undocumented, but it will show you that something is phoning home. Our guide to whether someone can tell if you read their email walks through the other signals.

What This Means for Your Inbox

Readdle's feature page claims "21+ million Users." Only Pro subscribers can track, and Readdle does not publish how many that is, so the tracked share of your inbox is unknown. What is known is who the tier targets: client facing teams. Those are the senders who time their follow ups to your opens, like a vendor chasing a renewal or the other side of a negotiation.

Readdle itself cautions that read statuses "have no legal significance. They simply show that the email has been opened." For you, the significance is practical. An open you did not intend to announce tells the sender you have seen the offer or the deadline, and that shifts the conversation before you have replied. That applies to every pixel tracker, which is why Spark belongs in the same bucket as the tools in our comparison of Gmail read receipt trackers.

How to Block Spark Read Statuses in Gmail

Readdle says it plainly: if the recipient blocks remote images or uses a privacy focused client, "you do not receive the Read Statuses indication." Your options, from bluntest to most convenient:

• Turn off automatic images in Gmail. Per Google's instructions: Settings, See all settings, scroll to "Images," click "Ask before displaying external images," then Save Changes. This stops every pixel, Spark's included, and also every logo and newsletter photo until you click to load them.
• Don't rely on Gmail's image scanning. Google says it stops senders learning your computer or location from an image, but not that it stops them learning you opened the email. It protects where you are, not your read status.
• Use a pixel blocking extension that keeps normal images loading but stops trackers. This is where honesty matters, because no tool we checked lists Spark by name.

How the Extensions Compare on Spark Specifically

We checked the public tracker lists and source code of four Gmail extensions for any Readdle or Spark Mail entry on September 23, 2026:

• Ugly Email: the public tracker list its developer publishes on GitHub has 58 entries and was last updated in May 2022. Its only "Spark" match is SparkPost. Ugly Email flags known trackers, so an unlisted Spark pixel would pass unmarked.
• PixelBlock: its public source on GitHub has not been updated since November 2015. We could not confirm whether the Chrome Web Store build differs.
• Trocker: its known tracker lists contain no Readdle entry, but its store description says that in Gmail it runs "a heuristic tracker detection" on the premise that "very tiny images are almost always trackers." Whether that catches Spark depends on the pixel's size, which is undocumented.
• Gblock: our built in list has no Spark entry either. Gblock also watches for unknown images of 150 bytes or less and reports them to Gblock so they can be added to the shared blocklist, and you can add any host you find via custom filters. The first open from a never seen pixel can slip through before detection.

The takeaway: size based detection is the only thing that stands a chance against an undocumented tracker like Spark's, and Gmail's "Ask before displaying external images" setting is the only guaranteed block. For a deeper look at the list based tools, see Ugly Email vs PixelBlock vs Trocker.

The Quick Answer

Spark Mail does track email opens, through a pixel based feature called Read Statuses that only Spark Pro and Enterprise users can send. The sender sees whether you opened the email, roughly when, and where you fall in the list of readers. Readdle says it does not process your IP address or device details, and keeps the read status until the sender deletes their account. Gmail will not warn you, and its image help page concedes that senders may learn you opened a message with images. To keep your reading private, stop the pixel from loading: turn off external images, or use a blocker that detects unknown pixels by size rather than only by name.