根据mailgun邮件列表中的变量更新条目的信息

Question

I have a mailing list on mailgun. The system adds a member to the mailing list with a variable named "id". Like this:

    $result = $mgClient->post("lists/$listAddress/members", array(
             'address'     => $email,
             'name'        => $name,
             'subscribed'  => true,
             'vars'        => '{"id":'.$id.'}'
            ));

Is there any way of updating that member's details (email and the name) based on the value of "id"?