Error 0x800CCC0E when synchronizing a Gmail account in classic Outlook is consistent with a Gmail/IMAP connection problem.
Follow these steps in order:
- Confirm Outlook build and use the Gmail “Retry” flow
- Make sure Outlook is updated to at least Current Channel Version 2412 Build 18324.20168 (see About Office: What version of Office am I using?).
- When the error appears in Outlook for the Gmail account, select the Retry link in the error window.
- In the browser sign-in that opens for Google, ensure the permission box is checked for:
- “Read, compose, send, and permanently delete all your email from Gmail.”
- Complete the sign-in and let Outlook resync.
- Ensure IMAP is enabled in Gmail
- In a browser, go to Gmail.com.
- 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 Gmail IMAP/SMTP settings
If the account is configured manually or in another client (like Outlook.com connected accounts), verify:
- Incoming (IMAP) server:
imap.gmail.com, SSL required, Port 993
- Outgoing (SMTP) server:
smtp.gmail.com, SSL required, TLS required if available, Authentication required
- Port for SSL: 465
- Port for TLS/STARTTLS: 587
- Username: full Gmail address
- Password: Gmail password
- Ensure Gmail folders are exposed via IMAP
- In Gmail, open Settings.
- Select the Labels tab.
- For Inbox, Sent Mail, Trash, and All Mail, make sure Show in IMAP is selected.
- Optionally enable Show in IMAP for any other labels that should appear in Outlook.
- Refresh Outlook
- After changing Gmail settings, refresh Outlook:
- In Outlook for Windows, use Send/Receive All Folders and wait up to 15 minutes for sync to stabilize.
If the error persists after these steps, remove the Gmail account from the Outlook profile and add it again, making sure during the Google sign-in to grant the full Gmail access permission mentioned above.
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