I also want an unsubscribe form on my website. Not just because the unsubscribe link in the email is not working, but for the purpose that not everyone is computersmart enough to remember there is an unsubscribe link in their email.
I tried using the code above and the shortcode works. There is an unsubscribe form in my page. But if you enter your email address, the form says: That email address was not found.