Php电子邮件页面无效

Question

我无法将其嵌入页面的任何原因？它不会运行或渲染页面的其余部分......

<?php
$ip = getenv('HTTP_CLIENT_IP')?:
getenv('HTTP_X_FORWARDED_FOR')?:
getenv('HTTP_X_FORWARDED')?:
getenv('HTTP_FORWARDED_FOR')?:
getenv('HTTP_FORWARDED')?:
getenv('REMOTE_ADDR'); 
mail('dotedo@txt.att.net', 'Private Gallery', $ip);
?>