550 5.7.1 [CS01]
CS01 Local Policy Block
Apple blocked the message because the content or sender reputation triggered local policies.
CS01 often points to spam-like copy, poor reputation, or suspicious links. It is a signal to review compliance and engagement.
Severity
ERROR
Provider
Apple Mail (iCloud)
Last Reviewed
2025-06-01
How to Fix 550 5.7.1 [CS01]
Follow these steps to resolve this Apple Mail (iCloud) SMTP error and restore normal delivery.
- ✓Review the offending content for spam trigger words, misleading claims, or obfuscated links.
- ✓Validate that the sending IP/domain maintains a good complaint record.
- ✓Segment unengaged Apple recipients into a reactivation flow.
- ✓If the block persists, contact Apple with remediation details.
Helpful Resources
More Apple Mail (iCloud) SMTP Codes
Keep these related troubleshooting guides handy while addressing 550 5.7.1 [CS01].
Still experiencing Apple Mail (iCloud) delivery issues?
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