SPF, DKIM, and DMARC are related email-authentication mechanisms defined by RFC 7208, RFC 6376, and the current DMARC specification, RFC 9989. They answer different questions. Read their results with the evaluated domains and alignment—not just the words pass or fail.
SPF: was the sending server authorized?
SPF checks whether the connecting mail server is permitted to send for the envelope sender domain. A forwarded message may fail SPF even when the original message was legitimate. SPF does not validate the visible From address by itself and does not inspect message intent.
DKIM: did a valid domain sign the message?
DKIM uses a cryptographic signature and a DNS-published key to verify that signed parts of a message were not changed after signing. Check the signing domain (d=). A valid signature proves control of that signing domain's key, not that the visible brand is trustworthy.
DMARC: does an authenticated domain align with From?
DMARC evaluates whether an SPF-authenticated or DKIM-signing domain aligns with the visible From domain. It also lets a domain publish a handling policy. A DMARC pass requires at least one aligned authentication path; both SPF and DKIM do not have to pass.
Common result meanings
| Result | General meaning | Important limitation |
|---|---|---|
pass |
The evaluated check succeeded | Does not prove safe content or intent |
fail |
The check did not satisfy its policy | Can result from misconfiguration or forwarding |
softfail |
SPF indicates the sender is probably unauthorized | Still requires context |
neutral / none |
No decisive policy or usable result | Not equivalent to pass |
temperror |
A temporary evaluation problem occurred | May succeed when retried |
permerror |
The published configuration cannot be evaluated correctly | Domain owner may need to fix DNS |
Use email header analysis to evaluate routing, identity, links, and context around these results. GetOpenInbox displays authentication results reported in received headers; it does not guarantee that a passing message is trustworthy.
References
- RFC 7208: Sender Policy Framework (SPF) — authorization of sending hosts for envelope domains.
- RFC 6376: DomainKeys Identified Mail (DKIM) Signatures — domain-level cryptographic message signatures.
- RFC 9989: Domain-Based Message Authentication, Reporting, and Conformance (DMARC) — the current DMARC standard, which obsoletes RFC 7489 and RFC 9091.
- RFC 8601: Authentication-Results — standardized header syntax for reporting authentication outcomes.