I have my own domain that I used to use for hosting random stuff and my email (nowadays it's just for the email). The email is a catch-all box.

I once got someone and their family's Disney World booking details sent to <theirname>@<mydomain>. It was a real thing, I could click the link and go view their booking at the official website. I have no idea what made that person to type out <mydomain> as their email, the domain is not even close to any publicly hosted email services or any company names. I kept getting more notifications of the upcoming Disney World trip so I ended up disabling that particular address so that those emails bounce.