7 SPF Record Mistakes That Hurt Email Deliverability

Publishing more than one SPF record

SPF expects a single policy for a hostname. Two records that both start with v=spf1 do not combine automatically; receivers can treat the result as a permanent error.

If several platforms send for your domain, consolidate the required mechanisms into one carefully managed policy.

Exceeding the DNS-lookup limit

SPF evaluation has a DNS-lookup limit. Include, a, mx, exists and redirect mechanisms can consume lookups, and nested includes count as well. A record that looks short can still exceed the limit because providers include other providers.

Audit the full lookup tree. Do not flatten records blindly without understanding how the included networks change over time.

Leaving obsolete senders authorized

Old marketing tools, former hosting providers and abandoned services often remain in SPF long after they stop being used. Each unnecessary authorization increases complexity and can expand the infrastructure allowed to send for your domain.

Maintain an inventory of legitimate senders and review the record during vendor changes.

Using the wrong qualifier

The difference between ~all, -all and other qualifiers matters. A hard fail should be introduced only when you are confident the legitimate sending sources are covered.

SPF by itself is not an anti-spoofing solution for the visible From address. Use DMARC alignment and policy for that purpose.

Editing SPF without checking DMARC alignment

SPF can pass for a Return-Path domain that is different from the From domain. DMARC then evaluates whether those domains align.

When troubleshooting deliverability, inspect both SPF authentication and the domain used for alignment instead of stopping at a simple pass result.

Assuming SPF protects forwarded email perfectly

Forwarding can break SPF because the forwarding server is not necessarily authorized by the original sender's policy. DKIM can survive forwarding more reliably when the message is not modified.

That is one reason DMARC allows aligned DKIM or aligned SPF to satisfy authentication rather than requiring both.