Registro DMARC
v=DMARC1; p=reject; rua=mailto:postmaster@campaigner.com

Servidores DNS Principal (mname) y Secundario (rname)
host: rssfwd.com
class: IN
ttl: 900
type: SOA
mname: ns-389.awsdns-48.com
rname: awsdns-hostmaster.amazon.com
serial: 1
refresh: 7200
retry: 900
expire: 1209600
minimum-ttl: 86400

Información TXT
host: rssfwd.com
class: IN
ttl: 300
type: TXT
txt: v=spf1 ip4:216.24.224.0/20 -all
entries: Array