Exact response pattern
550 5.7.0 Message rejected for policy reasonsPermanentGenericPolicy
What it means
The receiver permanently rejected the message under a local policy.
Likely causes
- Authentication failure.
- Content or reputation policy.
- Sender not authorized.
Recommended response
- Use the complete response to identify the policy.
- Fix the root cause before retrying.
Operational rule: Preserve the complete SMTP response, remote hostname, sending IP, envelope sender and timestamp. Never diagnose from the three-digit code alone.