Even worse, I have commonfirstnamecommonlastname@gmail.com and get several emails a day that I didn't sign up for. Now the person who did sign up isn't getting

Even worse, I have commonfirstnamecommonlastname@gmail.com and get several emails a day that I didn't sign up for. Now the person who did sign up isn't getting them and I have to figure out how to opt out of them. Sometimes these website accounts already have payment/personal details associated with them, which I now have access to (and indeed, sometimes have to view) in order to find the "stop sending me email" button. Always send the confirmation "did you sign up?" email. Always.