Servidores DNS Principal (mname) y Secundario (rname)
host: hs20.net
class: IN
ttl: 3600
type: SOA
mname: ns1-02.azure-dns.com
rname: azuredns-hostmaster.microsoft.com
serial: 1
refresh: 3600
retry: 300
expire: 2419200
minimum-ttl: 300

Servidor de Correo
host: hs20.net
class: IN
ttl: 300
type: MX
pri: 10
target: cluster3.eu.messagelabs.com

Servidor de Correo
host: hs20.net
class: IN
ttl: 300
type: MX
pri: 20
target: cluster3a.eu.messagelabs.com