Registro DMARC
v=DMARC1; p=none;

Servidores DNS Principal (mname) y Secundario (rname)
host: mapabook.com
class: IN
ttl: 14400
type: SOA
mname: ns1.siteground.net
rname: admins.siteground.com
serial: 1
refresh: 10800
retry: 3600
expire: 604800
minimum-ttl: 3600