553 5.7.2 [TSS11]
TSS11 Permanent Block
Yahoo permanently blocked the sender. Retrying without remediation will fail.
TSS11 usually follows spam complaints, compromised accounts, or repeated violations of Yahoo’s bulk sender policies.
Severity
CRITICAL
Provider
Yahoo Mail
Reference
TSS11
Last Reviewed
2025-06-01
How to Fix 553 5.7.2 [TSS11]
Follow these steps to resolve this Yahoo Mail SMTP error and restore normal delivery.
- ✓Halt traffic and investigate every stream that sends to Yahoo domains.
- ✓Close security gaps and document the fixes in a mitigation plan.
- ✓Provide proof of remediation to Yahoo support before resuming.
- ✓Send small, monitored batches once Yahoo confirms the unblock.
Helpful Resources
More Yahoo Mail SMTP Codes
Keep these related troubleshooting guides handy while addressing 553 5.7.2 [TSS11].
Still experiencing Yahoo Mail delivery issues?
Run your domain through our free deliverability tools or book a session with Bento's deliverability specialists.