SPF lookup checker

SPF has a hard limit of ten DNS lookups across mechanisms like include, a, mx, and redirect. Complex records that chain many providers together can silently cross that limit, returning permerror instead of a clean pass or fail and making deliverability harder to reason about. Start with your SPF record status and then check for multiple SPF records if things still look off.

If your SPF setup is complex, review the SPF lookup limit guide.

Learn the bigger picture in our Email Authentication Explained guide and compare SPF vs DKIM vs DMARC to understand how these protocols work together.

One-Minute Fix

Paste your SPF record into the lookup checker below to estimate how many DNS lookups it triggers. If you are close to or over ten, simplify your mechanisms, remove unused providers, or consolidate infrastructure so the record stays within the limit.

Example SPF record with lookups

DNS TXT

v=spf1 include:_spf.google.com include:sendgrid.net a mx ~all

In this example, each include, a, and mx contributes to the DNS lookup budget. The goal is to authorize your real senders while keeping the total number of lookups under the SPF limit.

Re-check

Check DNS lookups

Paste your SPF record to estimate how many DNS lookups it uses and see whether you are close to the SPF limit.

SPF DNS lookup checker

Paste a single SPF record. This helper counts includes, A, MX, and redirect mechanisms to estimate DNS lookups.

Why DNS lookups matter for SPF

Every time a receiver evaluates your SPF record, it has to follow include, a, mx, and redirect mechanisms. When the total exceeds ten lookups, SPF evaluation stops with a permerror. That means even a well-intentioned, complete record can fail in practice if it is too complex. This is especially common when multiple SPF records are published or when DNS lookup limits are exceeded.

Why this is a problem

If SPF regularly returns permerror, mailbox providers cannot use it as a reliable signal. That can cause DMARC to fail when SPF was supposed to provide alignment, and it can make otherwise healthy mail streams look unstable or poorly managed. For many senders the concrete symptom is a syntax error or a record that is too long for DNS to handle cleanly.

How lookup bloat affects deliverability

From a deliverability perspective, a simpler SPF record that stays under the lookup limit is almost always safer than a sprawling one that tries to list every edge case. Mailbox providers reward consistency; when your SPF result frequently breaks, it becomes harder to build and maintain trust with large receivers. You can see this clearly in neutral SPF results or when softfail vs fail decisions tip borderline mail into spam.

Common causes

Chaining many third-party providers together with separate include mechanisms.
Using a and mx mechanisms broadly across domains instead of targeting specific hosts.
Legacy or unused services that were never removed from the SPF record.
Redirect chains that pull in additional records without being obvious in the top-level policy.

What this page helps you check

This page does not perform a live DNS query. Instead, it gives you a fast, approximate count of how many DNS lookups your SPF policy is likely to trigger based on commonly costly mechanisms.

Live DNS lookup. No login. No saved domains. No tracking.

Next steps

Paste your current SPF record into the lookup checker.
Review the estimated lookup count and identify which mechanisms contribute most.
Remove obsolete services and simplify where possible.
Re-test until the SPF record stays safely under the ten-lookup limit.
Review the full troubleshooting guidance in the SPF Hub.
Check signing and selector issues in the DKIM Hub.
Review alignment and policy issues in the DMARC Hub.