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

Servidores DNS Principal (mname) y Secundario (rname)
host: guilfordmills.com
class: IN
ttl: 1800
type: SOA
mname: a1-20.akam.net
rname: hostmaster.guilfordmills.com
serial: 2025060601
refresh: 3600
retry: 600
expire: 604800
minimum-ttl: 300

Información TXT
host: guilfordmills.com
class: IN
ttl: 60
type: TXT
txt: v=spf1 -all
entries: Array