I found out, using "show original" on Gmail, that some business associates are embedding tracking into their sent emails (without any obvious warning/declaration), which tells them :

  1. If I have received the email in my inbox
  2. Number of times I have read it
  3. Also sends them notifications when I read it (the worst part)

These people are not part of my company but with whom I have to interact closely over long periods of time.

I have already enabled "Do not show external images" but it does not work. I have explored Google forums but no article seems to address this exactly.

This is how it shows up in the "show original" option in Gmail:

Snippet from the email

What can I do to stop the received/unread/read status of my received emails from being tracked by the sender?

Edit 1: Ghostery claims it can block this (https://apps.ghostery.com/hu/apps/mailtrack.io), but I'd prefer a DIY approach, and I don't trust Ghostery with all the data it will get access to.

Edit 2: As asked in comment, browser used by me is Firefox (I've seen it working successfully even with Chrome). Only red flag in email privacy tester was for DNS pre-fetch. No other warning.

No helpful reply yet even on Google forums: https://productforums.google.com/forum/#!topic/gmail/3VJbpH1RdGk

Edit 3: This is another snippet from "show original" in Gmail, 0 pixel image I guess:Show Original in Gmail

Maybe, Google is pinging the mailtrack server when I open the email (To download that "image" and show its own copy (thus generating a timestamp event)

  • From your question, it sounds like you are talking about Gmail in the browser (which browser?). If it's something else, please be very specific since solutions depend on the context. You can use emailprivacytester.com to determine what method(s) are not getting blocked. If you also include those in your question, you'll get better answers. – pseudon Oct 28 '17 at 0:45
  • Thanks for the links. I'm using Firefox 55. The emailprivacy tester only shows some DNS prefetch warning. – DS R Oct 29 '17 at 18:14
  • "I have already enabled "Do not show external images" but it does not work" - how do you know this? – Ethan Oct 30 '17 at 11:59
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    From comment below: I happened to suspect a person for tracking me and found out his email had mailtrack. Then I asked one a friend to install mailtrack and try tracking an email sent to me; it worked like a charm.. with gmail image blocking on. – DS R Oct 30 '17 at 12:26
  • DNS prefetch may well be the culprit. If emailprivacytester can detect it, anyone can, and it's basically a read receipt for that particular email. You may be able to turn off DNS prefetch in applicable browsers. Then test again. – pseudon Oct 30 '17 at 19:17

If you don't want third party software like Ghostery or PixelBlock, one way to stop tracking via email is to disable automatic image loading in Gmail. The tracking is usually done via tiny images, so stopping these images from being loaded will prevent your data from being sent back to the tracker.

ITworld has instructions for how to disable automatic image loading:


  • As I clarified in my question, I have already disabled automatic loading of external images, which is what your referenced article is pointing me to. I don't know why it doesn't work but that's that. – DS R Oct 27 '17 at 13:15
  • Ah, sorry, didn't see that. How do you know it's not working? Can you see the 1px image in your email? – freginold Oct 27 '17 at 13:55
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    I happened to suspect a person for tracking me and found out his email had mailtrack. Then I asked one a friend to install mailtrack and try tracking an email sent to me; it worked like a charm.. with image blocking on. – DS R Oct 27 '17 at 16:44
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    Did you leave enough time between the email hitting the server and you reading it to distinguish between a server DNS prefetch and actual client read tracking? – pseudon Oct 30 '17 at 20:02
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    Answer accepted; my settings for image blocking had been modified by admin user due to other problems, after image blocking, tracking doesn't work. – DS R Nov 1 '17 at 10:57

Send yourself an email from https://www.emailprivacytester.com/ and see what (if any) tracking vulnerabilities exist in your context (mail client, browser version, etc.)

Any single tracking vulnerability provides a vehicle for creating a time-stamped read receipt (and, depending on which vulnerability, potentially much more extensive information about your client).

Once the vulnerabilities are identified, you'll need to find browser settings (or a different client) that allow you to close ALL of the vulnerabilities.

In this particular case, you need to find a browser version and settings that will prevent DNS prefetch.

The emailprivacytester web site does note that:

Some mail servers do DNS lookups on these URLs as part of their spam filtering process, so you may see the IP address of the mail servers DNS resolvers here, as well as, or instead of, your own.

...so you may not be able to prevent it on a Gmail account if Google is in fact doing DNS lookups on the tracker link. But, if that's the case, it will only show the timestamp and IP of the Google server, and would not be a read receipt reflecting your behavior.

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