Servidores DNS Principal (mname) y Secundario (rname)
host: 52ch.cn
class: IN
ttl: 600
type: SOA
mname: dns.bizcn.com
rname: abuse.bizcn.com
serial: 19
refresh: 28800
retry: 14400
expire: 14400
minimum-ttl: 600

Servidor de Correo
host: 52ch.cn
class: IN
ttl: 120
type: MX
pri: 10
target: mx.mail.ym.163.com