Outlook is not synchronizing subscribed folders. Error code is (0x800CCC0E)

Question

Error code is (0x800CCC0E) Outlook is not synchronizingf subscribed folders and is not sending or receiving emails. Everything worked fine yesterday

Answer 1

Follow these steps in order, testing send/receive after each step:

1. Confirm internet connectivity
   Open a browser (Edge or Chrome) and browse to http://www.microsoft.com or http://www.bing.com. If these do not load, resolve the network issue first. Outlook cannot sync or send/receive without a working internet connection.
2. Check for general sync issues in Outlook
   In classic Outlook, go to the View tab on the Ribbon and select the Sync button to force a manual sync. Watch the status bar at the bottom for sync progress or errors. If sync does not start or completes with errors, continue with the next steps.
3. Verify account type and configuration
   If this is a third‑party account (Gmail, Yahoo, ISP IMAP/POP):
   • Ensure the account is set up with the correct account type and server settings from the provider.
   • For accounts that should use Outlook.com (for example, Hotmail.com or Live.com), make sure the account type is Outlook.com, not Exchange or Microsoft 365.
4. Check for OST/PST data file corruption (Exchange/IMAP)
   If this is an Exchange or IMAP account using Cached Exchange Mode:
   • Right‑click a problem folder in Outlook → Properties → Synchronization tab.
   • Compare Server folder contains and Offline folder contains. If they differ or items are missing, the local .ost file may be corrupted.
   • Close Outlook. Rename the .ost file as described in Issues when you synchronize your Exchange Server mailbox with your .ost file in Outlook.
   • Restart Outlook and allow it to resynchronize. After “Preparing for first use” completes, check if send/receive and folder sync work.
5. Repair Outlook data files if using a .pst
   If the account uses a Personal Folders File (.pst), run the Inbox Repair Tool (ScanPST) to repair the .pst as described in Repair Outlook personal folders file (.pst). A damaged .pst can cause send/receive failures and error codes like 0x800CCC0E.
6. Check for TLS 1.3 registry issue (IMAP/POP)
   If this is an IMAP or POP account and the error persists:
   • Open Registry Editor and navigate to the Protocols key as described in the “Outlook IMAP or POP server unexpectedly terminated the connection” article.
   • If TLS 1.3 appears under Protocols, export that key for backup, then delete the TLS 1.3 key and its subkeys.
   • Restart Outlook; if sync still fails, restart Windows and test again.
7. If the account is AOL IMAP and stopped recently
   For AOL accounts that suddenly stopped syncing:
   • Sign in to AOL webmail.
   • Either rename folders under Inbox (e.g., “Recipes” → “Recipes1”), or create new folders, move mail into them, then delete the old folders under Inbox as described in the AOL sync article.
   • Reopen Outlook and allow time for a full sync.

If, after these steps, Outlook still shows 0x800CCC0E and will not sync subscribed folders or send/receive, the next actions are to verify server settings with the mail provider and check for any provider‑side outages or blocks.

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References:

• I can't send or receive messages in Outlook
• Issues when you synchronize your Exchange Server mailbox with your .ost file in Outlook
• Synchronization problems occur in Outlook and in Outlook Web App
• Outlook IMAP or POP server unexpectedly terminated the connection, and the server was interrupted
• Outlook stops syncing AOL email
• Troubleshoot Outlook email setup