SPF & Lookup Limits

Sender Policy Framework (SPF) is your first line of defense, but it has a fatal architectural flaw: The 10-Lookup Limit.

The "PermError" Risk

The SPF standard (RFC 7208) limits the number of DNS lookups to 10 per check to prevent Denial of Service (DoS) attacks.

The Cyber Risk

If you exceed 10 lookups, receivers return a PermError. This invalidates your entire SPF record, causing legitimate emails to fail authentication and potentially land in spam.

Why modern businesses fail SPF

It's easy to hit the limit. Just a few common cloud services can break your record:

include:_spf.google.com (= 2 lookups)

include:spf.protection.outlook.com (= 2 lookups)

include:servers.mcsv.net (= 1 lookup)

include:spf.salesforce.com (= 3 lookups)

TOTAL 8 / 10 Used

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Scans your record for nested includes.
Resolves them to their underlying IP addresses.
Compresses your record into a single, highly efficient entry (0 lookups).
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