newsletter unsubscribe

Hello, I am finishing the design of a newsletter for a client, but they ask me to add a link below to unsubscribe from the list. We are not using databases or a very large list, so what I would like is to see the possibility of adding a button so that, when clicked, an email is automatically sent to my account with the subject unsubscribe and, obviously, the account from which it is sent. Is this possible to do? I think I’ve seen some of that, but I’m not a programmer so I’m not sure how to do it. I thank you in advance for any help. Greetings to all, Luis