Description:
------------
---
From manual page: http://www.php.net/filter.examples.validation
---

It seems that the filter_var() function doesn't quite work for all emails, at least not consistently.

Test script:
---------------
<?php

function domainExists($email) {
  if(filter_var($email,FILTER_VALIDATE_EMAIL)) {
    list($user, $domain) = explode('@', $email);
    if(checkdnsrr($domain, 'MX')) {
      return TRUE;
    }
    else {
      return FALSE;
    }
  }
  else {
    return FALSE;
  }
}

$rm = 'jane_doe@hotmail.com';

if(domainExists($rm) === TRUE) {
  echo '<p>It worked!</p>';
}
else {
  echo '<p>It didn\'t work!</p>';
}

?>

Expected result:
----------------
I expect the function in the test/sample script to return true and echo '<p>It worked!</p>'.

Actual result:
--------------
The actual result is '<p>It didn\'t work!</p>'.