What is SPF flattening?

SPF flattening replaces include chains with explicit IP mechanisms to reduce DNS lookups and avoid PermError.

Why do too many lookups break SPF?

SPF evaluation stops after 10 DNS lookups by standard, and going beyond that returns a permanent error.

Yes. Third-party sender IP ranges change, so flattened SPF records should be refreshed on a schedule.

Yes, long SPF TXT values can exceed DNS size guidance, so you must balance lookup count and record length.

Flattening is useful for lookup control, while includes are easier to maintain. The best choice depends on your risk and operations.

The SPF Flattening Tool helps you overcome the RFC limit of 10 DNS lookups by converting nested Includes into raw IP addresses.

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Automated follow-up sequences

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The SPF Flattening Tool helps you overcome the RFC limit of 10 DNS lookups by converting nested Includes into raw IP addresses.

AI-written reply suggestions

Automated follow-up sequences

Campaign open & click tracking

Unlimited connected accounts