Email troubleshooting guides
SPF troubleshooting, organized by problem
Diagnose SPF syntax, dependencies, evaluation paths, subdomains, and lookup limits.
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SPF dependency lookup returned NXDOMAIN or NODATAFind SPF include and redirect DNS lookups that return NXDOMAIN or NODATA, separately from SPF lookup-causing term limits.
SPF is not configured for the envelope sender domainDiagnose SPF missing on a bounce or MAIL FROM subdomain. Check the exact envelope domain, add only authorized senders, and verify safely.
SPF terms after all are ignoredDiagnose SPF includes and redirects placed after all. Find unreachable sender authorization, reorder the policy safely, and verify the result.
The SPF include or redirect target does not publish an SPF recordFind the exact SPF include or redirect target with no SPF policy. Diagnose a missing SPF dependency safely without removing legitimate sending services.
Primary sources: Primary technical reference.