Help Please > Fatal Error: undefined function: getmxrr()

programming
1

I am receiving the following error with my contact form which has been working perfectly until I used a new host. They say PHP is enabled so hopefully someone could give some advice on the problem. The contact page is on www.decipheruk.com/home.html on the contact page.
This is the error:

Fatal error: Call to undefined function: getmxrr() in D:\inetpub\vhosts\decipheruk.com\httpdocs\decipherukcontact.php on line 16

This is my PHP and this is line 16 " if(getmxrr($Domain, $MXHost)) "


<?php

$txtEmail = trim($_POST['txtEmail']);
$txtSubject = trim($_POST['txtSubject']);
$txtBody = trim($_POST['txtBody']);

function checkEmail($txtEmail) 
{
   if(eregi("^[a-zA-Z0-9_]+@[a-zA-Z0-9\-]+\.[a-zA-Z0-9\-\.]+$]", $txtEmail)) 
   {
      return FALSE;
   }

   list($Username, $Domain) = split("@",$txtEmail);
   
   if(getmxrr($Domain, $MXHost)) 
   {
      return TRUE;
   }
   else 
   {
      if(fsockopen($Domain, 25, $errno, $errstr, 30)) 
      {
         return TRUE; 
      }
      else 
      {
         return FALSE; 
      }
   }
}

if( isset( $_POST['submit'] ) )
{
    $errors = '';
    
    if(checkEmail($txtEmail) == FALSE) 
    {
    
        if( empty($txtEmail) )
        { 
            $errors .= "<br/><strong>You left your email address blank please fill it in...</strong><br/><br/>";
        } else { 
            $errors .= "<strong>Your E-mail address entered is not valid, please go back and try again.<br/><br/></strong>";
        }
    }
    
    if ( empty($txtSubject) ) { $errors .= "<strong>Please put a subject.<br/><br/></strong>"; }
    
    if ( empty($txtBody) ) { $errors .= "<strong>Please write your message.<br/><br/></strong>"; }

    echo $errors;
        
    if ( empty($errors) )
    {
        $sendTo = "me@mydomain.com";
        $subject = $txtSubject;
        $headers = "From: " . $txtEmail;
        $message = $txtBody;
        mail($sendTo, $subject, $message, $headers);
        header("location: http://www.mydomain.com/thankyou.html");        
    }
}

?>

Your help would be appreciated many thanks!

Joe