Registro DMARC
v=DMARC1; p=reject; rua=mailto:rua@dmarc.microsoft;ruf=mailto:ruf@dmarc.microsoft;fo=1:s:d

Servidores DNS Principal (mname) y Secundario (rname)
host: asur.com
class: IN
ttl: 3600
type: SOA
mname: ns1-07.azure-dns.com
rname: azuredns-hostmaster.microsoft.com
serial: 1
refresh: 3600
retry: 300
expire: 2419200
minimum-ttl: 300