What's up with the *-TY page? Isn't that itself a Thank You that wouldn't be linked directly in the email, or is it a misnomer?
As many people have already said in response, a fully reliable solution is simply not present. I do however like the suggestion made in a previous discussion on this topic to include a 1 pixel image in your email template (blending into the background) with a url behind it. The logic is this link is not visible, so a normal human being would not click on it. Therefore any person clicking this link would be highly suspected to be a bot.
Does anyone have experience with this solution and its accuracy?
The pixel tells you that one hit was from a mail scanner, but it doesn't tell you which subsequent hits (and even prior hits, depending on scanner behavior) are from the mail scanner vs. interactive human.
That is entirely true. It serves mainly to identify the suspected leads where mail scanners are active. You would need to further analyse these records to see the rest of their behaviour pattern and decide whether you want to exclude the entire lead from scoring on clicks or not. By no means a perfect solution, but from what I have seen so far the most likely to correctly identify leads with mail scanners running.
Might be different in different countries, doesn't seem to be that widespread around here yet. Mostly some large international companies, but SME not so much.
That's assuming you know when the scanner is being used.
Think about what you're trying with the pixel: any HTML rendering engine knows exactly how large that will appear to the end user (i.e. it's not meant to be clicked) without following it. So the correct security tactic is to ignore it, to not send any more signals upstream.
Interesting point. Only proves that it is extremely difficult to really catch the right people. I'm starting to warm up to your suggestion to exclude email clicks from scoring and success attribution alltogether.