SMTP code 5.2.2
What the knowledge base's own tables say about this code, and which articles say it — a description of the reply, never a placement prediction.
The knowledge base documents this code in more than one row. What tells those rows apart is the rejection text in your own log, not the code: read each line below against what your rejection says.
- Meaning
- Mailbox full, reported as permanent
- Next step
- Treat like a 4.2.2 that keeps recurring
- 4.2.2, in the same table
- Soft bounce: retry, and suppress if it keeps recurring (often an abandoned account)
From SMTP Enhanced Status Codes (RFC 3463) · Using the codes for bounce classification
- Test that tells causes apart
- A single recipient, and temporary
- Next step
- Treat it as a soft, temporary failure: retry, then suppress after repeated failures. It does not reflect on your reputation
- Rejection says…
- "quota exceeded", "mailbox full", "out of storage", 5.2.2
- Hypothesis
- The recipient's mailbox is full
From Delivery Troubleshooting Playbooks · Playbook A: message not delivered (bounced or rejected, 5xx)