E-Mail Eingabe testen preg_match("/^[a-z]+[a-z0-9]*[\.|\-|_]?[a-z0-9]+@([a-z]+[a-z0-9]*[\.|\-]?[a-z]+[a-z0-9]*[a-z0-9]+){1,4}\.[a-z]{2,4}$/", $email)