You will want to first craft your delete page that will delete or update that record in the db. You will want to setup the server behavior so that it is triggered on a get parameter, whatever you would like to call it.
Since the get parameter will be set to the id of the record you will use this as the key value in the update or delete server behavior.
Are you planning on updating the user's record to set an email columns value? If so then in your email you will add a regular link to the bottom of the message. Make sure to add in your get URL parameter here, I will refer to it as UserID. You then add in the recordset binding for the users id so the link might look like this:
<a href="http://yoursite.com/unsubscribe.php?UserID=<?php echo $row_Users['UserID'] ?>">unsubscribe</a>
When the user clicks on this link it should take them to this page with the update or delete on it, the page will use the id passed in the UserID get parameter as record key. Then just update the column or delete the record as needed.
