How to fix SPF too many lookups

SPF records are limited to 10 DNS lookups. Exceeding this limit causes SPF PermError and can break email authentication.

What SPF lookup limit means

SPF evaluation may trigger DNS lookups through include, a, mx, ptr, and exists mechanisms, and the redirect= modifier.

RFC rules limit SPF evaluation to a maximum of 10 DNS lookups. Exceeding this limit causes SPF PermError.

This limit exists to prevent excessive DNS recursion and abuse.

The following terms count toward the 10 lookup limit: include, a, mx, ptr, and exists mechanisms, and the redirect= modifier.

Nested include chains also count. A single include may trigger several additional lookups.

The ip4 and ip6 mechanisms do not count as DNS lookups.

When SPF exceeds the lookup limit, receiving servers may return SPF PermError.

This weakens SPF authentication, can break DMARC alignment, and increases the likelihood of spam placement or rejection.

Some receiving providers treat SPF PermError as SPF fail.

Remove unused include mechanisms.

Avoid chaining multiple email providers unnecessarily.

Flatten SPF records where appropriate.

Replace include mechanisms with explicit ip4 or ip6 ranges when practical.

Review third-party senders regularly and remove obsolete providers.

SPF flattening replaces include mechanisms with explicit IP address ranges.

This reduces DNS lookups but requires maintenance because provider IP ranges can change over time.

Automatic SPF flattening tools should be monitored carefully.

Use MXFend's SPF Checker to detect excessive SPF DNS lookups, SPF PermError conditions, and nested include chains.

SPF allows a maximum of 10 DNS lookups during SPF evaluation.

Yes. Each include mechanism counts as a DNS lookup and may trigger additional nested lookups.

Yes. Exceeding the SPF lookup limit causes SPF PermError and may increase spam placement or rejection risk.

Remove unnecessary include mechanisms, simplify SPF records, and flatten SPF where appropriate.