Status 5.3.0#
smtp;551 5.3.0 Unknown error
The receiver refused the message for good and points at a mail-system problem on the receiving side (enhanced status 5.3.0). Use the wording above to pin down the exact fix.
Email provider · 5.x.x permanent failure
Yandex SMTP 551 Errors: Every Bounce Response Explained
Every SMTP 551 response on record from Yandex (yandex.com), with the verbatim text, the enhanced status code, a severity rating and a plain-English fix.
The recipient is not local to this server and no forwarding path is offered. It is permanent, so send to the address the recipient actually uses.
- Provider
- Yandex
- Code
- 551 (5xx)
- Responses
- 1
- Highest severity
- Unclassified
Yandex SMTP 551 responses
Yandex SMTP 551 questions
›What does an SMTP 551 error from Yandex mean?
The recipient is not local to this server and no forwarding path is offered. It is permanent, so send to the address the recipient actually uses. At Yandex, it is a permanent rejection, and the specific reason is in the enhanced status code and message text of each response below.
›How do I stop Yandex from returning SMTP 551?
Match your bounce text to one of the responses below and follow its guidance. Recipient-side wording means fix the address. Authentication or reputation wording (SPF, DKIM, DMARC, blocklist) means fix your sending setup, and check Yandex's postmaster documentation.