AUTHPROBLEM.comEmail Authentication Analysis
Common Auth Problems
Email authentication issues often sit between SPF, DKIM, and DMARC rather than inside one record alone. A domain can have valid-looking DNS records but still fail because senders are missing, signatures do not align, forwarding changes the path, or enforcement was enabled before every sender was ready.
| Area | What To Check | Guide |
|---|---|---|
| SPF sender path | The sending IP, envelope sender, forwarding path, or lookup budget does not match the published SPF policy. | Open guide |
| DKIM signing | The selector, public key, signing domain, or message integrity does not line up with the message being delivered. | Open guide |
| DMARC alignment | SPF or DKIM may exist, but neither passes in a way that aligns with the visible From domain and the published policy. | Open guide |
Use the sections below to decide whether the first place to look is sender authorization, DKIM signing, DMARC alignment, or rollout policy.
Best Practices
- Treat SPF, DKIM, and DMARC as one deployment rather than three unrelated DNS records.
- Build a sender inventory before tightening policy.
- Use DKIM alignment wherever possible so forwarding does not leave DMARC dependent on SPF.
- Review aggregate DMARC reports before and after policy changes.
- Test real message paths, including third-party senders, scanners, helpdesks, and forwarding routes.
The combined view is useful because a DMARC failure may be caused by SPF, DKIM, vendor configuration, forwarding, DNS reliability, or a policy decision. Splitting findings by layer makes the next action clearer.