public function createSendGridMailer($username, $password, $options)
    {
        if (!$username) {
            throw new InvalidConfigException("Username cannot be empty.");
        }
        if (!$password) {
            throw new InvalidConfigException("Password cannot be empty.");
        }
        $sendgrid = new \SendGrid($username, $password , $options);

        return $sendgrid;
    }