diff --git a/inc/auth.php b/inc/auth.php
index 62a093de41993a232caae5ad6b0ccc94ad55c348..3966a4d47ebfc5c1335e67452f75e104076148b4 100644
--- a/inc/auth.php
+++ b/inc/auth.php
@@ -832,20 +832,6 @@ function act_resendpwd(){
     return false; // never reached
 }
 
-/**
- * Uses a regular expresion to check if a given mail address is valid
- *
- * May not be completly RFC conform!
- *
- * @link    http://www.webmasterworld.com/forum88/135.htm
- *
- * @param   string $email the address to check
- * @return  bool          true if address is valid
- */
-function isvalidemail($email){
-  return eregi("^[0-9a-z]([-_.]?[0-9a-z])*@[0-9a-z]([-.]?[0-9a-z])*\\.[a-z]{2,4}$", $email);
-}
-
 /**
  * Encrypts a password using the given method and salt
  *