generated: '2026-09-05'
method: probed
source: live TLS/HTTP probes of www.51offer.com and m.51offer.com plus DNS lookups of 51offer.com against 8.8.8.8,
  2026-09-05. Re-probed by hand after probe-domain-security.py recorded https:false for www.51offer.com on a transient
  connection failure - the host does serve HTTPS.
hosts:
- host: www.51offer.com
  https: true
  tls_version: TLSv1.2
  cipher: ECDHE-RSA-AES256-GCM-SHA384
  certificate_subject: CN=*.51offer.com
  certificate_issuer: C=CN, O=Beijing Xinchacha Credit Management Co., Ltd., CN=Xcc Trust DV SSL CA
  certificate_not_before: '2025-10-21'
  certificate_not_after: '2026-10-21'
  certificate_verify: ok
  hsts: false
  note: No Strict-Transport-Security header. TLS 1.3 not negotiated; the host settles on TLS 1.2.
- host: m.51offer.com
  https: true
  hsts: false
  note: Serves the same Swagger 1.2 documents at /api-docs.
domains:
- domain: 51offer.com
  dnssec: false
  caa: []
  spf: true
  spf_record: v=spf1 ip4:47.100.215.175 include:_s.corp-email.com -all
  dmarc: false
  dmarc_note: _dmarc.51offer.com returns NXDOMAIN
  mx:
  - 51offer-com.corpsmtp.net
  - 51offer-com.corpsmtp.cn
  - cnc.biz-email.net
  - mail.biz-email.net
  nameservers:
  - f1g1ns1.dnspod.net
  note: SPF is published with a hard fail (-all). No DNSSEC, no CAA and no DMARC record exists.