I can confirm part of this, in my last job I was a hotel manager and I could tell if you received and opened your confirmation email. I could even tell if you clicked where it had the latest cancellation date before receiving a penalty

This was a big deal during Covid, because we sent an e-mail with Covid policies and what was open. A lot of people complained in order to get a free stay, claiming that they were not told this/that. But I would see that they not received the email, and clicked on the email, and the date and time that they did.