Servidores DNS Principal (mname) y Secundario (rname)
host: 21ccnn.com
class: IN
ttl: 600
type: SOA
mname: ns15.bigwww.com
rname: hostmaster.hichina.com
serial: 2024042814
refresh: 3600
retry: 1200
expire: 86400
minimum-ttl: 600

Servidor de Correo
host: 21ccnn.com
class: IN
ttl: 600
type: MX
pri: 5
target: mxbiz1.qq.com

Servidor de Correo
host: 21ccnn.com
class: IN
ttl: 600
type: MX
pri: 10
target: mxbiz2.qq.com