454 4.7.0: sign-in failed on a temporary problem
Gmail could not complete your client's SMTP sign-in because of a passing problem on its side, and asks it to try again later.
- Gmail
- Provider
- Temporary (4xx)
- Class
- Sources checked
- Author
At a glance
- Code
- 454 4.7.0
- Provider
- Gmail and Google Workspace
- Temporary or permanent
- TemporaryThe sending server keeps the message and tries again later.
- Who has to act
- The sender. The fix is on the sending side: your domain, your server or your list.
- What the server says
454 4.7.0 Cannot authenticate due to a temporary system problem. Try again later.
What it means
Your client reached Google's SMTP service and tried to authenticate, but Google could not process the sign-in at that moment. The reply describes the problem as temporary and on Google's side, so the credentials are not necessarily wrong. Clients should wait and retry with exponential backoff; retrying in a tight loop can add a too-many-attempts block on top. Google's relay documentation treats this together with the too-many-attempts reply and suggests checking TLS, the IP allowlist and SMTP AUTH settings if it continues. The current table reads 'Cannot sign in'; the June 2025 version read 'Cannot authenticate', the wording quoted here.
Common causes
- A passing fault in Google's sign-in systems.
- Repeated sign-in attempts in a short time while that fault is happening.
How to fix it
- 01Wait and retry with increasing delays instead of signing in again at once.
- 02If it continues, confirm the client connects with TLS (port 587 with STARTTLS, or port 465) and that its credentials are current.
- 03For smtp-relay.gmail.com, check that your sending IP and HELO domain match the SMTP relay service setting.
- 04Check the Google Workspace Status Dashboard for an incident.
Sources
What this page rests on, checked on 20 Oct 2026. The explanation is ours; the reply text is the server's.
- Gmail SMTP errors and codes (Google Workspace Admin Help)knowledge.workspace.google.com
- Gmail SMTP errors and codes, version of June 2025 (Internet Archive copy)web.archive.org
- SMTP relay service error messages (Google Workspace Admin Help)knowledge.workspace.google.com
Related codes
- 454 4.7.0Too many sign-in attempts.Gmail is refusing SMTP sign-ins from your client for a while, because it tried to authenticate too many times in a short period.
- 454Temporary authentication or TLS failure.A login or a TLS handshake could not be completed because of a temporary problem on the server; the client should try again later without changing anything.
- 5.7.0Security or policy refusal, unspecified.The message or session was refused for a security or policy reason that the server did not describe more precisely, or chose not to reveal.
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