Authentication history

Immutable persisted observations.

Observed	Signal	Selector	Verdict	Fingerprint
2026-08-20T12:22:03+00:00	DMARC	—	VALID	`8c5d0ff023aa…`
2026-08-20T12:22:03+00:00	SPF	—	VALID	`1ff73dcee55c…`