Web Technician OnlineWhat does this mean?
SPF lets a receiving system compare a connecting sender address against a published policy for an envelope domain. It is not a check of the message’s visible From address alone, and it does not by itself guarantee inbox delivery. Knowing which domain was evaluated is essential to interpreting a result.
What should I check first?
List every service that actually sends on your behalf: mailbox provider, website forms, invoices and newsletters may use different infrastructure. Obtain each provider’s current instructions rather than copying a policy from another domain. Save the existing TXT records before making changes.
How can I diagnose the cause?
Use SPF DNS record checker to retrieve the policy at the evaluated domain. The local explainer can describe its terms, but it does not expand every include or count all DNS-dependent work. Inspect Authentication-Results in a real received message to see the SPF domain and result used by that receiver.
How do I fix it safely?
Publish a single coherent SPF policy with the required authorized sources, following provider guidance. Multiple separate v=spf1 policies at the same name are not a safe way to add senders. Avoid +all because it authorizes every address. Do not delete DKIM, DMARC or unrelated TXT verification records.
Verify the fix and know when to contact your provider
Test mail from each sending service and inspect full headers. A forwarding path can alter SPF behavior, so use DKIM and alignment evidence too. Ask the provider to review the complete policy if includes become complex or a legitimate sender fails. Share redacted headers and expected sender services, never SMTP credentials.
Work through these checks in order
- Send a test through each real source and record the receiver’s smtp.mailfrom domain. That is the domain to check for SPF; a visible From address alone may point you to the wrong policy.
- Use the DNS checker to count published matching policies, then compare the allowed services with current provider instructions. The local explainer does not expand recursive includes or validate sender addresses.
- Save the existing policy, consolidate approved sources into one record and retest each source. Preserve unrelated TXT records and ask the provider to assess lookup complexity if the policy has several dependencies.
Which tool can help?
SPF DNS record checker · SPF record explainer
DNS tools show one resolver’s public answers. Record explainers do not authenticate a message, and calculators do not monitor a server. Use the evidence alongside your provider’s logs.