The problem is that an unchecked checkbox does not get posted. You need a way to match the checkbox with the textbox, which can be done by using the index as a value (instead of the email), starting at 0. If you need the email you can create a hidden input array for them, similar to the textboxes.
You cannot just post variables to that page. You need to store the information somewhere in between (database, file). The display script just gets it's information from there. The admin script updates the database or file, not the page itself.