Registro DMARC
v=DMARC1; p=reject;

Servidores DNS Principal (mname) y Secundario (rname)
host: mercuryengineering.biz
class: IN
ttl: 3600
type: SOA
mname: ns1.blacknight.com
rname: hostmaster.blacknight.com
serial: 1274759521
refresh: 14400
retry: 7200
expire: 2419200
minimum-ttl: 3600

Información TXT
host: mercuryengineering.biz
class: IN
ttl: 3600
type: TXT
txt: v=spf1 -all
entries: Array