We pick i.root-servers.net, one of the 13 root servers (1), and ask it about ergo.com.ee and learn that ee is delegated to eight name servers (2), so we ask ee.aso.ee where we learn that ergo.com.ee is delegated to two name servers, including ns3.ergo.com.ee (3), so we ask that one and get the following answer:
Ergo.com.ee is a domain controlled by two domain name servers at com.ee. We are missing the IP:s of two servers: ns4.ergo.com.ee and ns3.ergo.com.ee. Incoming mail for ergo.com.ee is handled by two mail servers also at com.ee. Both are on the same IP network.