Gmail 454 4.7.0
Too many sign-in attempts (SMTP relay)
Gmail 454 4.7.0 means: too many sign-in attempts (SMTP relay). It is a temporary failure, so your server retries it. Gmail's SMTP relay rejected the sign-in attempts. Wait, then check the credentials and relay settings in the Google Admin console.
Gmail’s exact wording
Quoted from Google Workspace Admin Help: Gmail SMTP errors and codes, checked 2026-11-05. Placeholders are Gmail’s own.
Reply text
Too many sign-in attempts, try again later. For details, go to SMTP relay service error messages.
Reply text
Cannot sign in due to a temporary system problem. Try again later. For details, go to SMTP relay service error messages.
| Who sends it | Gmail and Google Workspace |
|---|---|
| Basic code | 454: Temporary authentication failure (RFC) |
| Enhanced code | 4.7.0: Other or undefined security status |
| Permanent or temporary | Temporary (4xx) |
| Verifying the list prevents it | No |
In practice
Both versions come from Google Workspace's SMTP relay service. Too many sign-in attempts usually means a device or app is retrying with wrong credentials in a loop. A temporary system problem means Google's side failed. Fix the credentials on the device, then wait before retrying, since rapid retries extend the lockout.
What the sender should do
Gmail's SMTP relay rejected the sign-in attempts. Wait, then check the credentials and relay settings in the Google Admin console.
Would verifying the list have prevented Gmail 454 4.7.0?
No
This reply is about your sending setup, the message or the receiving system, not about whether the address exists, so verifying the list will not prevent it.
Common questions
- What does Gmail 454 4.7.0 mean?
- Gmail 454 4.7.0 means: too many sign-in attempts (SMTP relay). It is a temporary failure, so your server retries it. Gmail's SMTP relay rejected the sign-in attempts. Wait, then check the credentials and relay settings in the Google Admin console.
- Should I retry after Gmail 454 4.7.0?
- Your sending server retries it automatically, because it is a temporary (4xx) failure. Investigate only if it keeps coming back over several hours.
- Would verifying my list have prevented Gmail 454 4.7.0?
- No. This reply is about your sending setup, the message or the receiving system, not about whether the address exists, so verifying the list will not prevent it.
Sources
- Google Workspace Admin Help: Gmail SMTP errors and codes (checked 2026-11-05)
- IANA: SMTP Enhanced Status Codes registry (checked 2026-11-05)
- RFC 4954: SMTP Service Extension for Authentication (checked 2026-11-05)
Registry and provider wording is quoted exactly; guidance is written by the SimpleVerifier Team.
SimpleVerifier Team · Last checked against the sources 2026-11-05