Registro DMARC
v=DMARC1; p=none; fo=1; rua=mailto:dmarc_rua@emaildefense.proofpoint.com; ruf=mailto:dmarc_ruf@emaildefense.proofpoint.com

Servidores DNS Principal (mname) y Secundario (rname)
host: SL-REVERSE.COM
class: IN
ttl: 21600
type: SOA
mname: ns1.softlayer.COM
rname: root.softlayer.COM
serial: 2021072803
refresh: 7200
retry: 600
expire: 1728000
minimum-ttl: 43200