Registro DMARC
v=DMARC1;p=reject;sp=reject;adkim=s;aspf=s

Servidores DNS Principal (mname) y Secundario (rname)
host: isletstudy.net
class: IN
ttl: 900
type: SOA
mname: ns-2031.awsdns-61.co.uk
rname: awsdns-hostmaster.amazon.com
serial: 1
refresh: 7200
retry: 900
expire: 1209600
minimum-ttl: 86400

Servidor de Correo
host: isletstudy.net
class: IN
ttl: 21600
type: MX
pri: 0
target: 

Información TXT
host: isletstudy.net
class: IN
ttl: 21600
type: TXT
txt: v=spf1 -all
entries: Array