Every campaign email you send out contains an unsubscribe link at the bottom, enabling customers to opt out of receiving any more campaigns from you.
When a customer unsubscribes, the Editor automatically removes their opt-in to receive email marketing from their profile in Customers.
In Marketing > Marketing settings, you can define the default page that customers land on when they unsubscribe from emails.
You can create a dedicated unsubscribe page in the Editor and hide it so it doesn't appear in your website's navigation. On the page, you can add any content you wish, for example a contact form for collecting feedback or a special offer to try to win back the customer.
Example of an unsubscribe page: