There is a problem with email metrics being inflated by many corporate email providers having some sort of link checker. That means that it appears there is instant and high engagement with your emails.
Whilst all marketers would love it if their emails were being instantly read, and clicked on, by their target audience the truth is that many people see a high volume of clicks immediately after sending as email systems check all of the links in the email are legitimate. This makes a lot of sense, if you have a good IT set up it will try to prevent spam and malicious links from reaching your inbox, but it may also make it harder for someone to get in touch.
With email metrics being a key tool in understanding what an audience wants to read about, and also more complicated email marketing automation built on user behaviour, how do you filter out the human vs bots?
There is no industry standard, and it ends up being down to individual marketers to come up with ideas. That's why we have a white text link on a white background in the footer of some of our emails. It is something that only a bot would see, and act upon, so it helps us filter out traffic that is not driven by a human.