Firefox@Lemmy.ml: Is it possible to install Firefox addons in Thunderbird?
Thunderbird's addon store is very lacking to compare to Firefox. Are there even technical limitations to this if Thunderbird use Firefox / Gecko under the hood?
No, add-ons have a list of applications they support coded into them, and it wouldn't make sense for a lot of them to be interchangeable. You don't need adblock in Thunderbird, you need spam filtering.
Trackers are basically embedded images in the email. If the image gets downloaded by your client, they can track if the email was opened. If you simply don't download images, there's no tracking.
In Mails normally you get the content you want sent. Tracking only happens if the content is not sent, but needs to be downloaded from within the app. Then the servers can see you got the mail.