title: mailchimp api delete user from list
body: <p>when user unsubscribes from list he can't subscribe again with the same email address. How can allow user to resubscribe to list?</p>
  
  <pre><code> $unsubscribe = $mailChimp-&gt;call('lists/unsubscribe',array(
                      'id'        =&gt; $list_id,
                      'email'    =&gt;  array('email' =&gt; $email),
                      true, 
                      true
                  ));
  </code></pre>