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

Servidores DNS Principal (mname) y Secundario (rname)
host: drmsa.com
class: IN
ttl: 3600
type: SOA
mname: 3dns1.firsthorizon.com
rname: hostmaster.3dns1.firsthorizon.com
serial: 2025021204
refresh: 10800
retry: 3600
expire: 604800
minimum-ttl: 86400