Registro DMARC
v=DMARC1; p=reject; fo=1; rua=mailto:dmarc_rua@emaildefense.proofpoint.com; ruf=mailto:dmarc_ruf@emaildefense.proofpoint.com

Servidores DNS Principal (mname) y Secundario (rname)
host: naids.ibm.com
class: IN
ttl: 21600
type: SOA
mname: dns1.p05.nsone.net
rname: hostmaster.nsone.net
serial: 1729786453
refresh: 43200
retry: 7200
expire: 604800
minimum-ttl: 7200

Servidor de Correo
host: naids.ibm.com
class: IN
ttl: 7200
type: MX
pri: 10
target: mx.sendgrid.net