$email,
'list' => $list,
'boolean' => 'true'
)
);
$opts = array('http' => array('method' => 'POST', 'header' => 'Content-type: application/x-www-form-urlencoded', 'content' => $postdata));
$context = stream_context_create($opts);
$result = file_get_contents($your_installation_url.'/unsubscribe', false, $context);
//check result and redirect
if($result)
header("Location: $success_url");
else
header("Location: $fail_url");
} else {
?>