Outlook Synchronizing Error 0x800CCC0E

Question

Outlook Synchronizing Error 0x800CCC0E

Outlook not synchronizing.

Please advise how to fix this as this just happened this morning.

There was a Microsoft update last night.

Answer 1

Hi Linda Abramson,

Based on what I’ve found, some users have recently experienced the same error (0x800CCC0E) after updates, and the behavior is currently being investigated in certain environments. In the meantime, you can try the workaround below, which has helped others in similar situations:

• Right-click the Windows Start button > select Run
• Type Regedit and click OK
• In the Registry Editor, paste this path into the address bar and press Enter: Computer\HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Identity\Identities
• Under Identities, select each subkey until you find the one associated with the email account that is not syncing
• Delete that specific identity key
• Restart Outlook and sign in again

You can also refer to this Microsoft article for more details: Users get errors 0x800CCC0E & 0x800CCC0F synchronizing Gmail and Yahoo accounts in classic Outlook

Please note that in this forum we don’t have access to your mailbox or server configuration, so we can only guide based on available documentation and similar reports. If Microsoft releases a confirmed fix, it will typically be shared through their official support channels.

I hope this helps for now. If anything is unclear or if you have more questions, feel free to reach out anytime.

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Answer 2

Error 0x800CCC0E is a sync/connectivity failure that can appear after updates when Outlook connects to POP/IMAP servers.

Based on the provided guidance, apply the following fix on the Windows machine where Outlook is installed:

1. Open Registry Editor
   1. Close Outlook.
   2. Press Windows + R, type regedit, and press Enter.
2. Check for TLS 1.3 under Protocols
   1. In Registry Editor, navigate to the Protocols key as documented in the article (under the system’s Schannel/TLS configuration).
   2. Under Protocols, look for a TLS 1.3 key.
   3. If TLS 1.3 exists:
      • Right‑click Protocols and select Export to save a backup of the current configuration (so it can be restored if needed).
      • After exporting, delete the TLS 1.3 key and all its subkeys.
3. Restart Outlook and Windows
   1. Close Registry Editor.
   2. Start Outlook and test synchronization.
   3. If sync still does not work, restart Windows and test Outlook again.

After this change, the Protocols section should no longer show any TLS 1.3 keys, which resolves the POP/IMAP sync failures described in the referenced guidance.

If the error persists after these steps, review the POP/IMAP account configuration with the mail provider, as the documented fix specifically addresses the TLS 1.3–related sync interruption.

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References:

• Outlook IMAP or POP server unexpectedly terminated the connection, and the server was interrupted
• Fixes or workarounds for recent issues in classic Outlook for Windows