SPF void lookup errors: find the empty DNS dependency

Define the decision

A void lookup is different from a timeout or an exceeded overall lookup budget. The relevant evidence is the evaluated DNS name, query result and point in the mechanism chain where it occurred.

Work through the procedure

1. Capture the receiver’s SPF error and the envelope domain.
2. Expand the policy with a diagnostic evaluator and note empty or nonexistent targets.
3. Confirm suspicious names directly against DNS, including spelling and removed vendor records.
4. Correct the responsible dependency and rerun the same evaluation.

Worked example

The following is a synthetic example for this procedure, not a customer result or performance benchmark.

Policy dependency: include:mail-old.example.com
DNS observation: target no longer has an SPF policy
Owner finding: retired sending service
Change: remove only after confirming no legitimate stream still depends on it

Read the result

An empty result can expose a typo, obsolete vendor setup or a provider-side change. Preserve the dependency chain when escalating; a screenshot saying SPF failed is too vague for the owner to act on.

Check before moving on

1. Distinguish NXDOMAIN, an empty answer and resolver timeout.
2. Validate a newly received message after DNS correction.

Limits and next action

Do not increase sending while the error remains unexplained. SPF evaluators and receivers may expose different wording, so keep the raw result with your diagnosis.

Source: RFC 7208: DNS lookup processing limits