Servidores DNS Principal (mname) y Secundario (rname)
host: sz-isp.com
class: IN
ttl: 500
type: SOA
mname: ns1.myhostadmin.net
rname: dnsconct.myhostadmin.net
serial: 2022091737
refresh: 43200
retry: 300
expire: 1209600
minimum-ttl: 3600

Servidor de Correo
host: sz-isp.com
class: IN
ttl: 321
type: MX
pri: 5
target: mxbiz1.qq.com

Servidor de Correo
host: sz-isp.com
class: IN
ttl: 321
type: MX
pri: 10
target: mxbiz2.qq.com