public static boolean isEmail(String email)
  {
    if ((email == null) || (email.length() < 1) || (email.length() > 256)) {
      return false;
    }
    Pattern pattern = Pattern.compile("^\\w+([-+.]\\w+)*@\\w+([-.]\\w+)*\\.\\w+([-.]\\w+)*$");

    return pattern.matcher(email).matches();
  }