Gmail / Google Workspace error guide

Gmail / Google Workspace SMTP 454 4.7.0: Temporary Auth Failure

Gmail / Google Workspace SMTP 454 4.7.0 usually means smtp authentication. Learn whether to retry, suppress the recipient, or fix sender setup.

Quick summary

Primary code
454 4.7.0
Provider coverage
Gmail / Google Workspace
Primary action
Retry later

How to handle 454 4.7.0

Match the provider, SMTP stage, endpoint, and diagnostic wording first, then use the checks below to decide whether to retry, suppress the recipient, or fix sender setup.

Gmail 454 4.7.0

SMTP authentication

Retry later

SMTP authentication means the receiving provider rejected the message for a provider-specific reason. Use the diagnostic text before deciding on retries or suppression.

Decision

A retry can work, especially after a short wait.

Confidence: high. Recipient validity: unknown.

Match this reply

SMTP stage
Authentication
Endpoint
SMTP submission
Too many attemptstemporaryauthentication

Start here

  1. 1

    Check SMTP credentials, OAuth token state, and whether SMTP AUTH is enabled for the mailbox or tenant.

  2. 2

    Refresh credentials or reconnect the sending account before retrying.

Confirm the cause

  1. Confirm the SMTP credentials, OAuth scopes, and token expiry for the sending account.
  2. Check whether SMTP AUTH is enabled for the mailbox or tenant.
  3. Reconnect the account or refresh credentials, then test with one message before resuming volume.

App handling

  • Queue a retry with backoff and keep the original SMTP reply attached to the attempt.
  • Slow or pause provider-specific sending if the same deferral repeats across many recipients.
  • Escalate to reputation, authentication, or volume review when retries keep failing.

Avoid

  • Do not suppress the recipient from a temporary response.
  • Do not keep the same retry pace if the deferral repeats across many recipients.
  • Do not ignore sender reputation or authentication if this keeps happening.
Common causes
  • SMTP credentials, OAuth permissions, or access tokens are invalid or expired.
  • SMTP AUTH is disabled for the mailbox, tenant, or account type.
  • The SMTP client is authenticating against the wrong endpoint or account.
Developer details
Fields to log
raw SMTP replyremote MX or hostSMTP stagereply codeenhanced codeprovidermatched rule idrecipientsending domaindecisiontimestamp
Classifier evidence
Specific cause
temporary auth failure
Evidence
official
support.google.com source 1

Not sure this is the right match?

Paste the full SMTP reply into the lookup tool. The classifier uses provider, endpoint, SMTP stage, reply code, enhanced code, token, and diagnostic text.

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