Enhanced status code

SMTP error X.7.20

No passing DKIM signature found

Updated Jul 1, 2026

The short answer

No passing DKIM signature found Common cause: Message has no DKIM signature that validates successfully

Quick fix

Fix DKIM signing, selector, DNS record, and message-modification issues

This code is written X.7.20 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

Fix DKIM signing, selector, DNS record, and message-modification issues

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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