Mail Domain Check

Live public DNS

SPF lookup counter

Expand the current include and redirect chain, count DNS-causing SPF terms, and compare the observed total with the RFC limit of 10.

Live DNS check

INPUT

Sending domain

The domain is sent to this service for a public DNS check. Free analytics retain only an irreversible domain hash and aggregate result metrics.

RESULT

Lookup budget

No domain checked

The result distinguishes a missing or duplicate SPF policy from a complete lookup count and an observed lower bound.

RFC budget model

Count mechanisms that can trigger DNS work

Countinclude, a, mx, ptr, exists

Each use consumes one term from the evaluation limit. Nested include policies add their own DNS-causing terms.

Countredirect modifier

A redirect target consumes budget and its policy must also be evaluated when no mechanism matched.

Do not countall, ip4, ip6, exp

These terms do not count toward the section 4.6.4 DNS lookup limit, though the full policy still needs correct syntax and authorization scope.

Primary references: RFC 7208 SPF DNS lookup limits and Google Workspace SPF troubleshooting.