Registro DMARC
v=DMARC1; p=reject;

Servidores DNS Principal (mname) y Secundario (rname)
host: b2up.com.br
class: IN
ttl: 900
type: SOA
mname: a.auto.dns.br
rname: hostmaster.registro.br
serial: 2026246500
refresh: 1800
retry: 900
expire: 604800
minimum-ttl: 900

Servidor de Correo
host: b2up.com.br
class: IN
ttl: 900
type: MX
pri: 0
target: 

Información TXT
host: b2up.com.br
class: IN
ttl: 900
type: TXT
txt: v=spf1 -all
entries: Array