return the TLD and Domain on any Wordpress install. (Usefull for mailer for example)

get_domain.php

<?php

  function domain_url() {
  
  	//get the full domain
  	$urlparts = parse_url(site_url());
  	$domain = $urlparts [host];
  	
  	//get the TLD and domain
  	$domainparts = explode(".", $domain);
  	$domain = $domainparts[count($domainparts)-2] . "." . $domainparts[count($domainparts)-1];
  	
  	return $domain;
  }

?>