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

Servidores DNS Principal (mname) y Secundario (rname)
host: ytimg.com
class: IN
ttl: 90
type: SOA
mname: ns1.google.com
rname: dns-admin.google.com
serial: 634692657
refresh: 900
retry: 900
expire: 1800
minimum-ttl: 60

Servidor de Correo
host: ytimg.com
class: IN
ttl: 300
type: MX
pri: 0
target: smtp.google.com

Información TXT
host: ytimg.com
class: IN
ttl: 300
type: TXT
txt: v=spf1 -all
entries: Array