I'll bet you didn't know (or maybe you do) that people/companies can track if and when you open your email? They may also be able to tell what device, browser. etc. you are using and much more! Just by you opening an email! Here's an article explaining how it works:
https://www.wired.com/story/how-email-open-tracking-quietly-took-over-the-web/ (https://www.wired.com/story/how-email-open-tracking-quietly-took-over-the-web/)
But there is a way to tell if this is happening. This is only for Gmail and for Chrome, currently. But other options are in the works. Here's a few Chrome extensions:
https://chrome.google.com/webstore/detail/pixelblock/jmpmfcjnflbcoidlgapblgpgbilinlem/related (https://chrome.google.com/webstore/detail/pixelblock/jmpmfcjnflbcoidlgapblgpgbilinlem/related)
https://chrome.google.com/webstore/detail/ugly-email/ldgiafaliifpknmgofiifianlnbgflgj (https://chrome.google.com/webstore/detail/ugly-email/ldgiafaliifpknmgofiifianlnbgflgj)
There are also services such as Senders that you filter your email through before it gets to you and shows you and/or removes the trackers:
https://sende.rs/ (https://sende.rs/)
Lots of info there... the email and other modes of communication on the internet get more hazardous all the while and it's not likely to get any better.
You've got that right...
Good info to know.
Was checking out the blockers but I see that they too can read your email?
Hmm, I could have sworn I've responded to this...
Anyhow, yes, they can the software used to detect the trackers can read your email but the personally do not nor keep any of the information within them...according to them. LOL