ฟังก์ชั่น mail() ส่งอีเมล์เข้า Hotmail ได้ แต่ส่งเข้า gmail ไม่ได้ ทำยังไงดีคะ

$MailTo = $_POST['MailTo'] ;
$MailFrom = $_POST['mail'] ;
$MailName = $_POST['name'] ;
$MailTel = $_POST['tel'] ;
$MailSubject = $_POST['subject'] ;
$MailMessage = $_POST['message'] ;

$Headers = "MIME-Version: 1.0\r\n" ;
$Headers .= "Content-type: text/html; charset=windows-874\r\n" ;

$Headers .= "From: ".$MailName." <".$MailFrom.">\r\n" ;
$Headers .= "X-Priority: 3\r\n" ;
$Headers .= "X-Mailer: PHP mailer\r\n" ;
if(mail($MailTo,$MailSubject,$MailMessage,$Headers))
{
  echo "<script>alert('Send Complete');window.location='contact.php';</script>";
  exit();
}else{
echo "Send Mail False" ;
}