Email Tracking Support
Email Tracking is a Chrome extension for Gmail on the web. SentCue hosts its site and API. Recipients do not install anything.
Before you install
Is email tracking legal?
Rules differ by country and by why you send the message. You decide whether you have a lawful basis, and whether notice or consent is required. SentCue does not geo-block recipients. This is not legal advice. Privacy.
Will the recipient know?
There is no “tracked by” footer. Recipients do not install the extension. Their mail client may still request a remote image, show an images warning, or expose the image URL in the HTML. We do not claim they cannot notice.
Can I get caught by spam filters?
Maybe. A tracking image is still a remote resource on outbound mail. We do not promise inbox placement. The product is for individual messages, not campaigns.
Does it work with Gmail labels and filters?
Yes, in Gmail on a computer browser. Labels and filters do not disable tracking. The Sent circle still needs a reliable row match; see below if a circle is missing.
Are activity signals proof someone read the email?
No. A blue circle means an activity signal was detected. That is not proof a person opened the message. For example, a mail provider or a security scanner can load pictures on its own, or you can create a signal by opening your own copy in Sent. How tracking works.
Just installed?
Four steps: pin Email Tracking, open Gmail on the web, enable tracking in the notice, then send a test email to yourself with a unique subject. Screenshots: Welcome.
The toolbar popup is the control panel: global On/Off, optional notifications, Recent, and History. In Gmail compose you can turn tracking on or off for one message. Global Off overrides individual message settings. When tracking is turned off in the extension, no messages are tracked.
How tracking works
It is a tiny image. When tracking is on, Email Tracking adds a 1×1 image with a random token to the email. When a mail client or Google’s image proxy loads that image after the Undo window, we show a blue circle in Sent. That is an activity signal, not proof a person read the mail. SentCue filters known automated requests, but no filter can identify every automatic image load.
Pixel origin: https://pixel.sentcue.com (alias t.sentcue.com for older messages). This support site is Cloudflare Pages and does not host the API.
No circle on a message you tracked?
The circle needs to identify one exact row in Sent, and Gmail does not always give it enough to work with. Two cases are known:
- Replies and forwards. Gmail sometimes does not expose a reliable message id for these, so no circle is drawn on the thread.
- A repeated subject. If an older untracked message has the same subject and recipient, the match is ambiguous and we leave the row unmarked rather than mark the wrong one.
Tracking itself is unaffected in both cases: the message is still tracked, activity is still detected, and the signal still appears in Recent and History. Only the marker in the Sent list is missing. A distinctive subject line makes the match reliable.
Limits
- Scheduled Send is not tracked. The email still goes out at the chosen time.
- Signals while Gmail can still undo the send are not counted.
- A repeat load within 10 minutes does not add another activity signal.
- Opening your own Sent copy, image proxies, or scanners can still create a blue circle.
History and reminders
Tracked sends appear under Recent in the popup and in History on this Chrome install only. Subject, recipient, and reminders stay in the browser; they are not sent to our server. You can set a reminder at a time, or only if no activity signal has appeared yet. Desktop notifications need a separate Chrome permission.
If you received a tracked email
Ask the sender to stop tracking you. Disable remote images in your mail app to reduce pixel loads. Privacy details: Privacy — if you received a tracked email.
Before you write (senders)
- Install the extension from the Chrome Web Store, and keep only one copy enabled.
- Reload the extension and refresh Gmail after updates.
- Tracking stays Off until you accept the disclosure.
- Scheduled Send is not supported.
Delete tracking data
Open the Email Tracking popup → Delete tracking data for this install (POST /delete-install). This clears server tokens for the install and local history/reminders on this computer. No Email Tracking or Google login is required. Email privacy@sentcue.com if the button fails.
Report a problem
Open the Email Tracking popup or history.html → Report a problem. The form sends only the problem type, extension version, browser version and an optional description you write yourself — never a message subject, body, recipient or thread id — to POST /feedback. Sending it needs your explicit consent.
Uninstalled Email Tracking?
Removing the extension opens the uninstall page automatically, where you can optionally tell us why. Answering is never required.