550 5.7.1
550 5.7.1 Low Domain Reputation
Gmail blocked the message because the sending domain has low reputation.
New domains, poor engagement, or recent spam complaints trigger Gmail’s domain reputation filters. The message is rejected outright.
Severity
ERROR
Provider
Gmail
Reference
Mitigation Portal
Last Reviewed
2025-06-01
How to Fix 550 5.7.1
Follow these steps to resolve this Gmail SMTP error and restore normal delivery.
- ✓Warm new domains slowly, starting with long-term engaged users.
- ✓Monitor domain reputation charts inside Google Postmaster Tools.
- ✓Align SPF, DKIM, and DMARC so authentication is airtight.
- ✓Segment aggressive promotions onto hardened domains or subdomains.
Helpful Resources
More Gmail SMTP Codes
Keep these related troubleshooting guides handy while addressing 550 5.7.1.
Still experiencing Gmail delivery issues?
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