public boolean validEmail() {

    email = tieEmail.getText().toString().trim();

    if (TextUtils.isEmpty(email)) {
      tilEmail.setError(Util.addCustomFont(this, getString(R.string.msg_email)));
      Util.requestFocus(this, tieEmail);
      return false;
    }

    if (Util.validEmail(email)) {
      tilEmail.setErrorEnabled(false);
    } else {
      tilEmail.setError(Util.addCustomFont(this, getString(R.string.incorrect_email)));
      Util.requestFocus(this, tieEmail);
      return false;
    }

    return true;
  }