Email Formats

{
  "mx": [
    "5 mengniu-cn.corpsmtp.net.",
    "10 mengniu-cn.corpsmtp.cn.",
    "15 mdn.corpemail.net.",
    "20 mdn.corp-email.cn."
  ],
  "spf": [
    "v=spf1 include:_s.corp-email.com -all"
  ]
}