Registro DMARC
v=DMARC1; p=reject; rua=mailto:mailauth-reports@google.com

Servidores DNS Principal (mname) y Secundario (rname)
host: youtube.om
class: IN
ttl: 21234
type: SOA
mname: ns1.googledomains.com
rname: cloud-dns-hostmaster.google.com
serial: 1
refresh: 21600
retry: 3600
expire: 259200
minimum-ttl: 300

Información TXT
host: youtube.om
class: IN
ttl: 300
type: TXT
txt: v=spf1 -all
entries: v=spf1 -all