public function validateEmailSender($email)
    {
        if (mb_strlen($email, 'UTF-8') > 255) {
            $this->addError(EmailConfigurationTransformer::EMAIL_SENDER, 'Sender email length has to be less or equal to 255');
            return false;
        }

        if (!empty($email)) {
            $emailValidator = new EmailValidator();
            if (!$emailValidator->isValid($email, new RFCValidation())) {
                $this->addError(EmailConfigurationTransformer::EMAIL_SENDER, 'Sender email must be an email address');
                return false;
            }
        }

        return true;
    }