What the SPF lookup limit means
SPF evaluation limits the DNS-querying terms used during one policy check. Include, a, mx, ptr, exists, and redirect can consume lookups, including lookups nested inside provider include records. When evaluation exceeds the limit, receivers return permerror even if the visible SPF string looks short.
The limit is evaluated at delivery time. Counting only the include words in your root record misses the nested mechanisms published by each provider.
Reduce lookups without weakening SPF
Remove services that no longer send, eliminate duplicate includes, and ask vendors for the smallest supported include. If a service offers a dedicated return-path domain, consider authenticating that subdomain separately so one root policy does not carry every sender.
Avoid blindly flattening provider records into IP addresses. Provider infrastructure changes, and a stale flattened policy can reject legitimate mail or authorize old networks. If flattening is unavoidable, it requires automated monitoring and refreshes.
Confirm the fix
After publishing the shorter policy, run an SPF check that follows nested includes. Send tests from each platform and inspect Received-SPF or Authentication-Results. A syntactically valid record is not enough if a legitimate sender was removed during cleanup.