问使用GCS配置我的主机，以便我的HTML网站可以使用PHP脚本发送电子邮件

EN

<?php
$field_name = $_POST['cf_name'];
$field_lastname = $_POST['cf_lastname'];
$field_subject = $_POST['cf_subject'];
$field_email = $_POST['cf_email'];
$field_message = $_POST['cf_message'];


$mail_to = 'cjddws@gmail.com';
$subject = .$cf_subject;

$body_message = 'From: '.$field_name."\n";
$body_message = .$field_lastname."\n";
$body_message .= 'E-mail: '.$field_email."\n";
$body_message .= 'Message: '.$field_message;

$headers = 'From: '.$field_email."\r\n";
$headers .= 'Reply-To: '.$field_email."\r\n";

$mail_status = mail($mail_to, $subject, $body_message, $headers);

if ($mail_status) { ?>
    <script language="javascript" type="text/javascript">
        alert('Thank you for the message. We will contact you shortly.');
        window.location = 'index.html';
    </script>
<?php
}
else { ?>
    <script language="javascript" type="text/javascript">
        alert('Message failed. Please, send an email to cjddws@gmail.com');
        window.location = 'index.html';
    </script>
<?php
}
?>