550 5.7.22: no DKIM signature from the From domain
The message has DKIM signatures that verify, but none is from the domain in the From header, which the receiving server requires.
- Standard
- Provider
- Permanent (5xx)
- Class
- Sources checked
- Author
At a glance
- Code
- 550 5.7.22
- Provider
- Standard SMTP codes
- Temporary or permanent
- PermanentRefused for good: the message comes back to the sender, and resending it gets the same answer.
- Who has to act
- The sender. The fix is on the sending side: your domain, your server or your list.
- What the server says
550 5.7.22 No valid author-matched DKIM signature found
What it means
X.7.22 is a special case of X.7.21. The signatures verify, but the domain in their d= tag does not match the author address in the From header field, and this receiver requires one that does. This is the situation DMARC alignment deals with: a message signed only with the email service provider's own domain passes DKIM yet fails the alignment check. RFC 7372 pairs it with reply 550, so the refusal is permanent. The fix is to sign with your own domain.
Common causes
- Your sending service signs with its own domain instead of yours.
- Mail sent through a third party (a CRM, a helpdesk) that is not set up to sign for your domain.
How to fix it
- 01Set up DKIM signing with your own domain in every service that sends as you.
- 02Publish the DKIM records each service gives you.
- 03Compare the d= value in the DKIM-Signature header of a test message with your From domain.
Sources
What this page rests on, checked on 20 Oct 2026. The explanation is ours; the reply text is the server's.
Related codes
- 550 5.7.21No acceptable DKIM signature.The message has at least one DKIM signature that verifies, but none meets the receiving server's own requirements, so it was refused.
- 550 5.7.20No valid DKIM signature.The receiving server requires a valid DKIM signature and found none that passed verification, so it refused the message.
- 550 5.7.26Multiple authentication checks failed.The message failed more than one authentication check, for example SPF and DKIM, and the receiving server's policy rejects it.
Further reading
All 105 standard codesEvery code in the wikiPaste your own bounce