Servidores DNS Principal (mname) y Secundario (rname)
host: mailshell.net
class: IN
ttl: 2560
type: SOA
mname: b.ns.mailshell.net
rname: hostmaster.mailshell.net
serial: 1790053768
refresh: 16384
retry: 2048
expire: 1048576
minimum-ttl: 2560

Servidor de Correo
host: mailshell.net
class: IN
ttl: 86400
type: MX
pri: 10
target: b.mx.mailshell.net

Servidor de Correo
host: mailshell.net
class: IN
ttl: 86400
type: MX
pri: 10
target: c.mx.mailshell.net