No time to listen to the podcast, but almost all email tracking comes in yw forms. Doctored links. so you click personalized links in the email to identify you on the web site, or web bugs which are image files linked to personalized URLs on the web site to identify you, although any remote image in an email can perform that function. (the twitter image in emails and web sites reports a great deal of information to twitter simply be the image being loaded, even if you are not affiliated with twitter in anyway.) Thunderbird does sort of break the cycle on twitter but it opens the invisible image in your browser instead. Something that is being worked on.

The only solution for the first is to not click links in email, but going to their site may not be much better. As an obvious example, note how Ebay tells you what you recently looked at.

The solution to the second is to not allow remote images in email. The default in Thunderbird. Although the instant gratification mob will turn it on because they have to see the pictures.

There is no way to tell exactly what a links is until it is clicked, so there is no App that will be able to monitor for you and block them. At the very best such an app would monitor for known links. But as the links are usually personalized, you have little hope of someone else developing a list for you to use.

Dear Matt. Thanks for taking the time to give such a detailed reply to my question. I can't hit the 'problem solved' button as your last paragraph explains it well; there really is no app that can completely solve this problem. Your tips on recommended email behavior and how web bugs behave in email and the internet are informative. It's always good to learn something new to help with these kinds of problems. You helped me in this regard. All the best and have a good day!