550 5.7.0
550 5.7.0 Proofpoint Block
Proofpoint, Apple’s filtering partner, blocked the sending IP for spam or abuse.
Proofpoint maintains Apple’s IP blocklist. If your IP is listed, Apple will block the message until Proofpoint clears the incident.
Severity
CRITICAL
Provider
Apple Mail (iCloud)
Last Reviewed
2025-06-01
How to Fix 550 5.7.0
Follow these steps to resolve this Apple Mail (iCloud) SMTP error and restore normal delivery.
- ✓Use the mitigation URL in the bounce to request delisting after remediation.
- ✓Document the root cause (compromised account, list abuse, etc.) in the request.
- ✓Tighten outbound spam monitoring and throttle suspicious behaviour.
- ✓Warm alternative IPs in case the review takes several days.
Helpful Resources
More Apple Mail (iCloud) SMTP Codes
Keep these related troubleshooting guides handy while addressing 550 5.7.0.
Still experiencing Apple Mail (iCloud) delivery issues?
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