Defaults.Exposed

Defaults.ExposedSeptember 2026 censusv10 registry › SPF policy strength

SPF policy strength

Methodology v10 · canonical ID spf-policy-strength · Email Security · scored · census as of September 5, 2026

A weak SPF only warns; a strict one actually blocks forgeries.

Definition

Canonical IDspf-policy-strength
CategoryEmail Security
Grade impactScored, counts toward the grade
PassThe SPF record ends in a hardfail all-mechanism (-all), telling receivers to reject unauthorized senders.
FailThe record ends in ~all (softfail), ?all (neutral), or +all (permits anyone), or no SPF exists.
Example (passing)v=spf1 include:_spf.example-mailer.com -all

No-data rule: when this check couldn't be determined for a domain (timeout, SERVFAIL, redacted source) it returns N/A and is excluded from that domain's scoring denominator: "couldn't determine" is never counted as a failure. "Determined absent" is a real fail.

Prevalence across the census

18.2% of graded domains publish SPF with a hardfail (-all) policy (57,704,425 of 316,600,902, as of September 5, 2026).

Softfail (~all) records count toward SPF presence but not full policy strength.

Census denominator: 316,600,902 graded domains. Aggregates only: never an individual domain's result.

Fix it

Plain-English impact, cost of ignoring it, and step-by-step remediation: defaults.exposed/fix/spf

Cite this check

Defaults.Exposed, "SPF policy strength (spf-policy-strength)", Grading Methodology v10 (census as of September 5, 2026). https://defaults.exposed/methodology/spf-policy-strength

Permalink: https://defaults.exposed/methodology/spf-policy-strength · All 34 checks: v10 registry · Machine-readable: /methodology/checks.json · Licence: open data