Based on customer feedback, we have added Beta support for external secondary DNS servers with our primary DNS service. This feature allows you to specify additional secondary DNS servers in addition to the Nettica servers. This feature also works with secondary DNS service providers. You can learn how to configure this service here:
This feature is free and available to all customers. This is a very advanced topic. You must really understand secondary DNS in order to make use of this feature. Please contact support if you have any problems.