Error 0x800CCC0E on one email account

Gary Jones 0 Reputation points
2026-11-02T17:15:53.5866667+00:00

I am suddenly getting this constant popup error on Moderator note: PII ******@gmail.com, an address I've had for months now.

Outlook | Windows | Classic Outlook for Windows | For home
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  1. AI answer

    2026-11-03T00:32:56.0066667+00:00

    If this Gmail account is configured in classic Outlook for Microsoft 365, remove its saved OAuth credentials and sign in again to clear the recurring 0x800CCC0E synchronization error.

    Microsoft fixed the matching service issue on March 20, 2026, but saved Gmail credentials can still require refreshing, particularly after a password change.^1^

    Refresh the Gmail credentials

    1. Close Outlook completely.
    2. Open Start, search for Credential Manager, and open it.
      • On Windows 10, it may be under Control Panel → Credential Manager.
    3. Select Windows Credentials.
    4. Under Generic Credentials, expand entries beginning with: MicrosoftOffice16_Data:OAUTH2
    5. Identify entries whose complete names include: tp_google_imap_Oauth2
    6. Select Remove for the Gmail OAuth entries. There may be two or four for an account.
    7. Restart Outlook.
    8. When prompted, sign in to the affected Gmail account and approve the requested Gmail access.
    9. If synchronization does not begin immediately, close and restart Outlook once more.

    This removes saved authentication tokens; it does not remove the Gmail account or its messages.

    If the Gmail password was changed recently, another supported option is to wait about one hour for the existing OAuth token to expire, after which Outlook should request sign-in again.^1^

    If the error continues

    Remove only the identity registry key belonging to the affected account:

    Registry changes carry risk; delete only the subkey whose displayed email address matches the affected Gmail account.

    1. Close Outlook.
    2. Right-click Start → Run.
    3. Enter regedit, then select OK.
    4. Paste this path into Registry Editor’s address bar:
    Computer\HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Identity\Identities
    1. Select each subkey under Identities until the values show the affected Gmail address.
    2. Right-click only that matching identity subkey and select Delete.
    3. Restart Outlook and sign in to Gmail again.

    Microsoft documents this as the fallback when clearing Credential Manager does not restore synchronization.^1^

    If the account is not actually hosted by Gmail, or this is not Outlook for Microsoft 365, these incident-specific steps may not apply; the complete Send/Receive error text and the account type—IMAP or POP—would then be needed to determine the correct server-side or profile repair.

    References

    1. Users get errors 0x800CCC0E & 0x800CCC0F synchronizing Gmail and Yahoo accounts in classic Outlook | Microsoft Support
    AI-generated content may be incorrect. Read our transparency notes for more information.

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  2. Emma1-N 14,890 Reputation points Microsoft External Staff Moderator
    2026-11-03T00:14:07.6233333+00:00

    Welcome Gary Jones,

    Please note that our forum is a public platform, and we will modify your question to hide your personal information in the description. Kindly ensure that you hide any personal or organizational information the next time you post an error or other details to protect personal data.  

    Thank you for posting in the Microsoft Q&A Forum. I'm sorry you're getting this error popup. Error 0x800CCC0E usually means that classic Outlook can't connect to the mail server for that account.

    To help me assist you better, please answer these questions:

    • The address in your post has two "@" signs. Is the account a standard @gmail.com address, or does it use your own domain?
    • Is this a personal account, or a work/business account (for example, Google Workspace, or Outlook installed under a business Microsoft 365 licence)?
    • Does the error appear when sending, receiving, or both? Do your other accounts in Outlook still work normally?
    • Did anything change recently, such as a password change, a Windows or Office update, or new antivirus or VPN software?

    While you gather that information, please try these steps:

    Step 1: Check the account outside Outlook Sign in to the account in a web browser (for Gmail, mail.google.com). If you get a security alert, a password reset prompt or a request to verify your identity, complete it first. A blocked sign-in on the provider's side can cause Outlook to fail connecting.

    Step 2: Start Outlook in Safe Mode Close Outlook. Press Windows key + R, type outlook.exe /safe, and select OK. If the error doesn't appear in Safe Mode, an add-in is likely the cause. In normal mode, go to File > Options > Add-ins, choose COM Add-ins next to Manage, select Go, and turn off the add-ins one at a time.

    Step 3: Remove the account and add it again (recommended if it's a Gmail account) Older Gmail connections can stop working when the saved credentials are no longer accepted. Re-adding the account uses Google's own sign-in window.

    • Go to File > Account Settings > Account Settings, select the account and choose Remove
    • Then select File > Add Account. Enter your email address and select Connect

    Looking forward to your update.

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