Enhanced status code

SMTP error X.7.22

No valid author-matched DKIM signature

Updated Jul 1, 2026

The short answer

No valid author-matched DKIM signature Common cause: Passing DKIM signature does not match the From domain

Quick fix

Configure DKIM alignment with the author domain

This code is written X.7.22 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

Configure DKIM alignment with the author domain

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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