setDomainCheck example

        if (array_key_exists('mx', $options)) {
            $this->setValidateMx($options['mx']);
        }

        if (array_key_exists('deep', $options)) {
            $this->setDeepMxCheck($options['deep']);
        }

        if (array_key_exists('domain', $options)) {
            $this->setDomainCheck($options['domain']);
        }

        return $this;
    }

    /** * Sets the validation failure message template for a particular key * Adds the ability to set messages to the attached hostname validator * * @param string $messageString * @param string $messageKey OPTIONAL * @return Zend_Validate_Abstract Provides a fluent interface * @throws Zend_Validate_Exception */