What this configuration means
Each section below is shown because the observed records match its condition. The explanations are reviewed text selected by the data, not generated from it.
DMARC enforces rejection
facebook.com publishes p=reject. Receivers that honour DMARC refuse mail using this domain in From unless SPF or DKIM aligns. This is the strongest published posture; it depends on every legitimate sender — including third-party platforms — having an aligned path, and on the aggregate reports the record requests to catch regressions.
A single mail exchanger
Inbound mail depends on one published host, smtpin.vvv.facebook.com. That host belongs to Self-hosted or other, which provides its own redundancy behind the name. A single MX is normal for hosted mailbox providers and a risk for self-hosted ones.
No common DKIM selectors found
None of the selector names commonly used by major platforms resolve under _domainkey.facebook.com. DKIM has no enumeration mechanism, so the domain may sign with a selector this check does not try; absence here is not proof that DKIM is unused. It does mean no platform with a conventional selector is publicly visible.
MTA-STS is published
facebook.com declares a transport-security policy in testing mode. Senders report failures without refusing delivery, which is the recommended stage before enforcement. TLS-RPT is also published, so transport failures are reported.
Change history
No change has been observed since the first snapshot on 2026-09-17. The domain is re-checked regularly and a new entry appears here when any record above changes.
How to read this report
The grade summarizes two records only: A means an enforcing DMARC policy with SPF hard fail; B enforcing DMARC with SPF; C monitoring-only DMARC or a weak SPF qualifier; D one of SPF or DMARC missing; F neither published. It is a prioritization aid for the public control plane, not a statement about deliverability, reputation or the security of the organization behind the domain.
DMARC policy is discovered with the RFC 9989 DNS tree walk, so a subdomain with no record of its own is reported with the organizational policy it inherits. DKIM selectors are discovered from common names only; a domain may sign with selectors this check does not try. Everything on this page comes from public DNS as observed on 2026-09-19; caches and split-horizon DNS can show different values elsewhere.
If you operate facebook.com and want a record corrected or the report removed, contact Mailybox.