SPF record checker

Find and validate the SPF record of a domain and review common configuration errors.

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What the SPF record checker does

This tool looks up the SPF record published for a domain in DNS and validates its basic structure. It reports common problems such as a missing version prefix, invalid separators, a missing all mechanism, or an unrecognized mechanism.

SPF, or Sender Policy Framework, is a DNS-based email authentication method. A domain publishes a TXT record listing the servers and services authorized to send email on its behalf. Receiving mail servers can check that record and reject or flag messages from unauthorized senders.

Why SPF matters

Email spoofing is common, and SPF is one of the main tools for reducing it. When a domain publishes a correct SPF record, receivers have a way to distinguish legitimate senders from impostors. This improves deliverability for legitimate mail and reduces the chance that forged messages reach inboxes.

SPF works alongside DKIM and DMARC. DKIM adds a cryptographic signature to messages, and DMARC ties the results of SPF and DKIM to a policy for handling failures. SPF alone is not a complete email security setup, but it is a foundational part of it.

How to interpret the result

The checker reports errors when it finds structural problems. A record that does not start with v=spf1 is not recognized as SPF. Invalid separators usually mean malformed syntax between mechanisms. A missing all mechanism leaves the default behavior ambiguous, and an invalid mechanism name means the record contains a token that receivers will not understand.

If the record passes basic validation, review its mechanisms for correctness. Common mechanisms include ip4, ip6, include, a, mx, and exists. The all qualifier at the end determines what happens to senders not matched by earlier mechanisms. Be cautious with +all, which authorizes everyone.

Common SPF mistakes

Multiple SPF records. More than one TXT record starting with v=spf1 causes lookup failures.
Too many DNS lookups. SPF has a lookup limit; excessive includes can cause permerror results.
Missing senders. Legitimate services not included in the record, causing delivery problems.
Permissive all. A policy that authorizes all senders defeats the purpose.
Stale includes. Third-party services no longer used but still authorized.

Practical workflow

Check the record for your main domain and for any subdomains that send mail. Confirm that every sending service is included and that unused ones are removed. Keep the record within lookup limits, and review it after changing email providers. Test with real messages to confirm authentication passes.

Limitations

The checker validates basic syntax and reports structural issues. It does not send test emails or verify that all legitimate senders pass authentication, and it does not check DKIM or DMARC configuration.