421 SPF Check Failed
SPF Check Failed
Orange rejected the message because the sending IP is not authorised in the domain’s SPF record.
Orange validates SPF before accepting the DATA command. Missing or misconfigured SPF records will block the message entirely.
Severity
ERROR
Provider
Orange
Last Reviewed
2025-06-01
How to Fix 421 SPF Check Failed
Follow these steps to resolve this Orange SMTP error and restore normal delivery.
- ✓Add the sending IP or include mechanism to the domain’s SPF record.
- ✓Keep SPF lookups below the 10-lookup limit by flattening includes where possible.
- ✓Publish matching reverse DNS (PTR) records to support SPF validation.
- ✓Coordinate with ESP partners to ensure their IPs are covered.
Helpful Resources
More Orange SMTP Codes
Keep these related troubleshooting guides handy while addressing 421 SPF Check Failed.
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