--- cacert/includes/general.php	2014-10-28 12:21:30.724020976 +0100
+++ general.php	2014-10-28 12:34:15.754475968 +0100
@@ -537,18 +537,10 @@
 		if(preg_match("/^([a-zA-Z0-9])+([a-zA-Z0-9\+\._-])*@([a-zA-Z0-9_-])+([a-zA-Z0-9\._-]+)+$/" , $email))
 		{
 			list($username,$domain)=explode('@',$email,2);
-			$dom = escapeshellarg($domain);
-			$line = trim(`dig +short MX $dom 2>&1`);
-#echo $email."-$dom-$line-\n";
-#echo `dig +short mx heise.de 2>&1`."-<br>\n";
 
-			$list = explode("\n", $line);
-			foreach($list as $row) {
-				if(!strstr($row, " ")) {
-					continue;
-				}
-				list($pri, $mxhosts[]) = explode(" ", trim($row), 2);
-			}
+            $mxhosts = array();
+            getmxrr($dom,$mxhosts);
+
 			$mxhosts[] = $domain;
 			array_walk($mxhosts, function(&$mx) { $mx = trim($mx, '.'); } );