The 421 4.7.0 soft bounce is a temporary policy rejection, often from Google. Learn what triggers it and how to fix rate limiting or new IP issues.
4.7.0
| Component | Value | Meaning |
|---|---|---|
| Class | 4 | Persistent transient failure (temporary) |
| Subject | 7 | Security or policy |
| Detail | 0 | Temporary Policy Rejection |
Per RFC 3463 Enhanced Mail System Status Codes. Class (X) = severity, Subject (Y) = category, Detail (Z) = specific condition.
The receiving server temporarily rejected your email due to a policy check — usually rate limiting, reputation throttling, or a new-sender hold. Retrying after a delay will usually work.
Google 421 4.7.0 is a generic temporary hold, often for new IPs or reputation concerns. Back off and retry.
📖 Google Workspace / Gmail documentation →These are real bounce message formats you might receive. Paste yours into the Bounce Decoder for instant analysis.
421 4.7.0 Try again later, closing connection 421-4.7.0 Our system has detected an unusual rate of unsolicited mail
Paste your full NDR email, SMTP error line, or mail log fragment to get an instant plain-English diagnosis.
Open the Bounce Decoder →