We pick h.root-servers.net, one of the 13 root servers (1), and ask it about webmail.reference.eutelsat.fr and learn that fr is delegated to six name servers (2), so we ask d.nic.fr where we learn that eutelsat.fr is delegated to three name servers, including rmbnse01.eutelsat.fr (3), so we ask that one and get the following answer: