The error indicates a problem with how the third Gmail account is authorized and/or configured for IMAP, even if the other two accounts work.
Follow these steps specifically for the failing Gmail account:
- Enable IMAP in that Gmail account
- Sign in to the problematic Gmail account in a browser.
- Select Settings (gear icon) > See all settings.
- Go to the Forwarding and POP/IMAP tab.
- Under IMAP access, select Enable IMAP.
- Select Save Changes.
- Verify the server settings in Outlook
When adding or repairing the account in Outlook, ensure the IMAP/SMTP settings for this Gmail account match the following:
- Incoming mail (IMAP) server:
imap.gmail.com- Requires SSL: Yes
- Port: 993
- Outgoing mail (SMTP) server:
smtp.gmail.com- Requires SSL: Yes
- Requires TLS: Yes (if available)
- Requires Authentication: Yes
- Port for SSL: 465
- Port for TLS/STARTTLS: 587
- Account name/username: full Gmail address
- Password: the correct password (or app password if using one)
- Incoming mail (IMAP) server:
- Re-run the Google sign-in/consent for this account in Outlook
For classic Outlook, this specific error can occur if, during the browser sign-in for this Gmail account, the consent box was not checked to allow full mail access. Remove or repair only the failing Gmail account and, when Outlook opens the Google sign-in page for that account again, ensure the following permission is checked:
- “Read, compose, send, and permanently delete all your email from Gmail.”
- If the account still fails while the others work
- Remove just the problematic Gmail account from the Outlook profile.
- Confirm IMAP is enabled for that Gmail account (step 1).
- Add the account back in Outlook, carefully completing the Google sign-in and granting the full mail permission above.
These steps target the specific IMAP/authorization issue that affects a single Gmail account even when others in the same Outlook profile are working.
References: