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SMTP error X.7.24

SPF validation error

Updated Jul 1, 2026

The short answer

SPF validation error Common cause: SPF evaluation itself failed due to a DNS or configuration error

Quick fix

Check SPF syntax, DNS availability, and lookup limits

This code is written X.7.24 because the reason is the same whether the failure is temporary (a 4 first digit) or permanent (a 5). Read the first digit of your own bounce to know which applies.

How to fix it

Check SPF syntax, DNS availability, and lookup limits

Related codes

X.7.0 Other or undefined security status X.7.1 Delivery not authorized X.7.2 Mailing list expansion prohibited X.7.3 Security conversion required but impossible X.7.4 Security features not supported X.7.5 Cryptographic failure
All SMTP error codes
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