Index: trunk/plugins/virtuser_file/virtuser_file.php
===================================================================
--- trunk/plugins/virtuser_file/virtuser_file.php	(revision 4010)
+++ trunk/plugins/virtuser_file/virtuser_file.php	(revision 4485)
@@ -41,5 +41,5 @@
 
 	        if (count($arr) > 0 && strpos($arr[0], '@')) {
-		        $result[] = idn_to_ascii(trim(str_replace('\\@', '@', $arr[0])));
+		        $result[] = rcube_idn_to_ascii(trim(str_replace('\\@', '@', $arr[0])));
 
 		        if ($p['first']) {