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 :
- If I have received the email in my inbox
- Number of times I have read it
- 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:
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
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)