使用MailGun API验证电子邮件地址

我可以使用MailgunAPI发送电子邮件,但是当我尝试验证电子邮件地址时,我会收到一个403错误(通过 An HTTP Error has occurred! Check your network connection and try again. 这是一个错误消息)。

$mg = Mailgun::create($private_apikey);
$validation = $mg->get('address/private/validate', array('address' => $email));

$mg = Mailgun::create($public_apikey);
$validation = $mg->get('address/validate', array('address' => $email));

怎么了?