I once had to convince a marketing department not to track a certain link in an email because it was literally breaking our reset-password process. For some reason, the "#" in our URL was munged in a way that Safari didn't like, which lead users to a 404 page. Happily, our email service gave us an easy way to not track a particular link in an email. 30 second fix. It took weeks to talk them into not tracking an email reset link. They kept suggesting tech solutions that they saw as reasonable, forcing me to point out why X wasn't actually that reasonable. I finally got the okay to remove it when it was pointed out that we were onboarding a huge number of customers, and that email was the way they were going to log onto the system. Freaking marketing. I swear...