Registro DMARC
v=DMARC1; p=reject; fo=1;  rua=mailto:dmarc_rua@emaildefense.proofpoint.com; ruf=mailto:dmarc_ruf@emaildefense.proofpoint.com

Servidores DNS Principal (mname) y Secundario (rname)
host: i-businesslockbox.com
class: IN
ttl: 7200
type: SOA
mname: NS23.WORLDNIC.com
rname: namehost\@WORLDNIC.com
serial: 122111813
refresh: 10800
retry: 3600
expire: 604800
minimum-ttl: 3600

Información TXT
host: i-businesslockbox.com
class: IN
ttl: 7200
type: TXT
txt: v=spf1 -all
entries: Array