We pick b.root-servers.net, one of the 13 root servers (1), and ask it about translate.sk and learn that sk is delegated to seven name servers (2), so we ask sns-pb.isc.org where we learn that translate.sk is delegated to three name servers, including ns1.websupport.sk (3), so we ask that one and get the following answer:
The two mail servers mail1 and mail2.websupport.sk together
There are several thousand of domains that use the two mail servers mail1 and mail2.websupport.sk together, hereafter referred to as "mail server group 1".
Most of those use name server group 1 (example: zenmarlinfli.com, vulmcz.com and rdx.cz ). Worth noting is that most of the domains that use name server group 1 use mail server group 1.
The three name servers ns1, ns2 and ns3.websupport.sk together
There are several thousand of domains that use name server group 1.
Most of those use mail server group 1 (example: annacentrum.sk, picocatering.sk and videni.cz ). Worth noting is that most of the domains that use mail server group 1 use name server group 1.
Three quarter of them use the primary name server ns1.websupport.sk (example: dnc.sk, moo.sk and kusa.sk ). Worth noting is that most of the domains that use the primary name server ns1.websupport.sk use name server group 1.