Gmail app password revoked: replace the specific credential safely

Define the decision

Google revokes app passwords when the main account password changes. Other causes can also interrupt access, so preserve the authentication error and compare it with the timing of the account change before generating replacements.

Work through the procedure

1. Confirm the mailbox account and recent credential changes.
2. Check whether OAuth is available and preferred for this connection.
3. If app-password access remains authorized, generate a new dedicated credential and update the protected mailbox setting.
4. Test SMTP and IMAP, then remove any obsolete credential that remains active.

Worked example

The following is a synthetic example for this procedure, not a customer result or performance benchmark.

Account password changed: Monday
Mailbox authentication failures begin: Monday
Likely relationship: old app password revoked
Verification: new authorized connection passes send-and-reply tests

Read the result

The timeline supports a diagnosis but should be verified by the actual result. A new app password will not fix a wrong host, disabled protocol or unrelated TLS error.

Check before moving on

1. Update the intended mailbox without exposing the secret.
2. Review missed replies before resuming follow-ups.

Limits and next action

Do not reuse the same secret across unrelated tools. If the original change followed suspected compromise, coordinate recovery with the account owner.

Source: Google: app-password revocation behavior