Registro DMARC
v=DMARC1; p=none;

Servidores DNS Principal (mname) y Secundario (rname)
host: boxalud.com
class: IN
ttl: 3600
type: SOA
mname: ns1-04.azure-dns.com
rname: azuredns-hostmaster.microsoft.com
serial: 1
refresh: 3600
retry: 300
expire: 2419200
minimum-ttl: 300