If your Primary DNS is being Managed by No-IP, we can allow zone transfers and notifications to DNS servers outside of our network. You’ll need to contact our support department to set this up. When making this request, please make sure to note the IP addresses of the name servers you wish us to allow zone transfers to.
Note: Keep in mind that No-IP has a very robust anycasted DNS network and sometimes adding third party DNS servers can make your DNS response times slower.