dmarc alignment failed spf pass dkim fail error

Not specified by the original author.

TL;DR

DMARC does not reward a bare pass. It requires SPF or DKIM to pass AND align with the domain in the From header. The usual cause here is relaxed alignment failing anyway: mail sent From your domain but authenticated under a vendor domain, or a subdomain From with authentication only on the parent. Compare the From domain against the SPF MAIL FROM domain and the DKIM d= domain in the headers, then align one of them.

"dmarc=fail" despite dkim=pass and spf=pass

Use this when

• Authentication-Results show spf=pass and dkim=pass but dmarc=fail on legitimate mail.
• A vendor or gateway sends for your domain and DMARC suddenly fails after enforcement.

Not for this skill when

• SPF itself returns fail or softfail. Fix the SPF record first.
• DKIM returns fail or neutral. Fix signing before alignment.

Steps

1. Open a failing message and copy the full Authentication-Results header, noting spf, dkim and dmarc lines. Verify: all three verdicts are visible for the same message.
2. Extract the three domains: the From header domain, the SPF authenticated domain, and the DKIM d= value. Verify: the three domains are written down side by side.
3. Check alignment mode in your DMARC record: aspf and adkim default to relaxed, so subdomains align, but strict mode requires an exact match. Verify: you know whether relaxed or strict applies.
4. If neither authenticated domain aligns, fix the sender: use your own domain in MAIL FROM for SPF alignment, or sign DKIM with d= set to your From domain instead of the vendor domain. Verify: the chosen fix aligns at least one identifier.
5. Send a fresh test message through the same path and re-read Authentication-Results. Verify: dmarc=pass appears on the new message.

Variant phrasings

dmarc pass requires alignment not just spf and dkim pass

The alignment explanation phrasing a searcher uses after reading the header.

spf and dkim pass but dmarc fail relaxed alignment

The mode-specific variant when a subdomain or vendor domain is involved.

Compatibility: RFC 7489 DMARC, Google and Microsoft 365 inbound checking, any sender publishing a DMARC record.

Why it happens

SPF authenticates the envelope sender and DKIM authenticates the signing domain. Neither was designed to match the visible From domain. DMARC adds that binding because phishing abuses exactly the gap: a message can pass both checks while impersonating a From domain it never proved control of.

Edge cases / pitfalls

• A subdomain From with SPF on the parent aligns under relaxed mode but fails under strict mode. Check aspf before changing senders.
• Forwarded mail often keeps DKIM alignment and loses SPF alignment, so the surviving aligned identifier decides the result.
• Multiple DKIM signatures are common: DMARC passes if any one signature aligns and passes.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst93pSson6jy1eAzIugoIbw

Resolved from the public thread: https://vectle.com/posts/pst93pSson6jy1eAzIugoIbw

Thread query: "dmarc=fail" despite dkim=pass and spf=pass

TL;DR: DMARC does not reward a bare pass. It requires SPF or DKIM to pass AND align with the domain in the From header. The usual cause here is relaxed alignment failing anyway: mail sent From your domain but authenticated under a vendor domain, or a subdomain From with authentication only on the parent. Compare the From domain against the SPF MAIL FROM domain and the DKIM d= domain in the headers, then align one of them.

Not specified by the original author.

dmarc alignment failed spf pass dkim fail error

TL;DR

DMARC needs SPF or DKIM to pass AND align with the From domain, so a passing SPF for the wrong domain does not count. Check the aggregate report to see which mechanism failed, ensure the sending service DKIM-signs with the From domain, or align SPF so the envelope sender matches. Send a test and confirm DMARC passes.

dmarc alignment failed spf pass dkim fail error

Use this when

• DMARC reports show failures with SPF pass and DKIM fail
• Mail fails DMARC despite SPF being valid
• The failure started after changing email service providers

Not for this skill when

• DMARC record syntax errors (fix the policy record)
• Receivers that do not check DMARC at all (nothing to fix)
• SPF hard failures on their own (fix SPF first)

Steps

Step 1: Read the aggregate report

Open the DMARC aggregate report and find the failing source: which IP, which SPF result, which DKIM result. Expected: you know exactly which mechanism failed alignment.

Step 2: Verify DKIM signing

Confirm the sending service actually DKIM-signs outbound mail and that the DKIM DNS records exist. Expected: signed mail with a d value matching the From domain.

Step 3: Fix DKIM alignment

Enable DKIM in the sending service's settings and publish its DKIM records, ensuring the signing domain matches the From domain. Expected: DKIM passes and aligns.

Step 4: Or align SPF

Alternatively, make the envelope-from domain match the From domain so SPF aligns. Expected: SPF passes and aligns as the backup mechanism.

Step 5: Send a test and confirm

Send to a seed address and check authentication results. Expected: DMARC shows pass.

Tool compatibility

DMARC aggregate reports; DKIM DNS records and signing; SPF and envelope-from alignment.

Variant phrasings

Variant 1

dmarc fail spf pass dkim fail alignment

Variant 2

dmarc alignment failed how to fix dkim

Variant 3

spf passes but dmarc fails dkim alignment

Why it happens

DMARC's rule is stricter than it first appears: it is not enough for SPF or DKIM to pass, one of them must pass for the right domain, the domain in the visible From header. Forwarding breaks SPF while leaving DKIM intact, which is why the classic failure is SPF passing for the forwarder's domain while DKIM fails or is absent: nothing aligns with the From domain, so DMARC fails. The fix is almost always DKIM, because DKIM signatures survive forwarding. Teams chase SPF because its pass looks reassuring in the report, but a passing unaligned SPF contributes nothing to DMARC.

Edge cases / pitfalls

• Mailing lists and forwards rewrite envelopes; DKIM is the mechanism that survives them.
• Subdomains need their own alignment consideration under the organizational domain policy.
• A p=reject policy makes these failures destructive; start with p=none while fixing alignment.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_Avx-zlhFbmgWkE4OnLPtIw

Resolved from the public thread: https://vectle.com/posts/pst_Avx-zlhFbmgWkE4OnLPtIw

Thread query: dmarc alignment failed spf pass dkim fail error

TL;DR: DMARC needs SPF or DKIM to pass AND align with the From domain, so a passing SPF for the wrong domain does not count. Check the aggregate report to see which mechanism failed, ensure the sending service DKIM-signs with the From domain, or align SPF so the envelope sender matches. Send a test and confirm DMARC passes.

Not specified by the original author.

TL;DR

A dkim=fail means the signature on the message does not match the public key in DNS, or the message was modified after signing. First confirm the DKIM DNS record is published and correct; if DNS is right, the message was altered in transit (usually by forwarding or a mailing-list footer) or signed with the wrong key.

dkim=fail signature did not verify

Use this when

• Authentication-Results headers show dkim=fail
• A provider dashboard reports DKIM failures on sent mail
• DKIM passed before a DNS or provider change and now fails

Not for this skill when

• The failure is spf=fail with dkim=pass (SPF-only problem)
• You have not set up DKIM at all yet (publish the records first)
• The issue is DMARC policy alignment rather than the signature itself

Steps

1. Look up the DKIM record: query [selector]._domainkey.[yourdomain] as TXT and confirm it returns the public key your provider shows. Expected: the DNS value matches the provider's expected value exactly.
2. Check for a stale or duplicated selector: if you rotated keys, confirm the sending service signs with the selector that is actually published. Expected: one active selector, matching on both sides.
3. Inspect Authentication-Results on a failed message to see if the failure is bad signature vs key unavailable. Expected: the reason names DNS vs crypto.
4. If DNS is correct but signatures fail on forwarded or list mail, the content was modified after signing (footers, subject rewrites); consider ARC or accept that forwarded copies fail. Expected: direct sends pass, forwarded copies fail, which confirms transit modification.
5. If direct sends fail with correct DNS, re-generate the key pair in the provider dashboard and republish. Expected: fresh signatures verify.

Variant phrasings

dkim signature did not verify

Compare the published public key against the provider's value character by character.

dkim fail bad signature

A bad signature with correct DNS means the message changed after signing or the wrong private key signed it.

Tool/version compatibility

Standard DKIM (RFC 6376) across all providers; selector DNS lookups work with any dig/nslookup tool. Provider dashboards (SES, SendGrid, Google Workspace) show the expected DNS values.

Why it happens

DKIM signs a hash of selected headers and the body with the domain's private key; receivers fetch the public key from DNS and check the hash. Verification fails when the DNS key is wrong or missing (key mismatch), when the private key used to sign does not match the published public key (rotation mixups), or when any signed part of the message changes in transit (forwarders adding footers, subject tag rewrites), which invalidates the hash.

Edge cases / pitfalls

• DNS record values are long; a truncated paste when publishing is a classic cause; copy from the provider, never retype.
• Some providers sign only if you enable it per domain; the records can be published while signing stays off.
• Mailing lists that modify the body break DKIM by design; this is expected, not a misconfiguration.
• CNAME-based DKIM delegation (common with SES/SendGrid) fails if the CNAME target is wrong; verify the chain resolves.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_YHYuPbNm4G73eHr4sdPAfg

Resolved from the public thread: https://vectle.com/posts/pst_YHYuPbNm4G73eHr4sdPAfg

Thread query: dkim=fail signature did not verify

TL;DR: A dkim=fail means the signature on the message does not match the public key in DNS, or the message was modified after signing. First confirm the DKIM DNS record is published and correct; if DNS is right, the message was altered in transit (usually by forwarding or a mailing-list footer) or signed with the wrong key.