Registro DMARC
v=DMARC1; p=reject;

Servidores DNS Principal (mname) y Secundario (rname)
host: myhealthyexchange.info
class: IN
ttl: 21600
type: SOA
mname: ns3.cernerns.com
rname: please_set_email.absolutely.nowhere
serial: 688917614
refresh: 10800
retry: 3600
expire: 2592000
minimum-ttl: 900

Información TXT
host: myhealthyexchange.info
class: IN
ttl: 21600
type: TXT
txt: v=spf1 -all
entries: Array