SMTP 550 5.7.26. — Unauthenti(92) email
Domain: Email.Priority: High
What does this error mean?
The message is rejected because the authentication of the sender domain is insufficient according to the policy of the recipient.
Probable causes
- SPF
- DKIM
- DMARC
Verification and resolution
- Check SPF
- check DKIM
- control DMARC alignment
Precaution: Do not modify DMARC without analyzing the path of sending.
← Return to the basis of the codes of error
Quick diagnostic.
To diagnose SMTP code 550 5.7.26 in the Email domain, start with the following check: Check SPF. Then check the result against this probable cause: SPF. Save the context and time of appearance to compare behavior before and after correction. Priority level indicated: High.