Registro DMARC
v=spf1 include:spf.mail.faidns.com ~all

Servidores DNS Principal (mname) y Secundario (rname)
host: bjbihua.cn
class: IN
ttl: 600
type: SOA
mname: dns23.hichina.com
rname: hostmaster.hichina.com
serial: 2025042413
refresh: 3600
retry: 1200
expire: 86400
minimum-ttl: 600