error code 0x800CCC0E

Question

Gmail inbox in old outlook not synchronizing-when I switch to new outlook all is fine

Answer 1

Hi,

Many users are reporting this issue. For most of them, clearing the Credentials and one other step is helping.

https://www.yourwindowsguide.com/2026/03/gmail-not-working-in-outlook.html

• Press Windows + S, type Credential Manager, and open it.
• Click Windows Credentials.
• Scroll to Generic Credentials.
• Find entries starting with MicrosoftOffice16_Data:OAUTH2.
• Expand each entry.
• Hover over MicrosoftOffice16_Data:OAUTH2 to see the full name containing tp_google_imap_Oauth2 (these are Gmail credentials).
• Click Remove for each MicrosoftOffice16_Data:OAUTH2 entry.
• Remove both credentials for the affected Gmail account.
• Optional: To identify the correct Gmail account before deleting:
  • Open Registry Editor.
  • Paste this path in the address bar: Computer\HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Identity\Identities
  • Check the Identity subkeys.
  • The number at the beginning of the identity key matches the number in the MicrosoftOffice16_Data credential.
• After removing the credentials:
  • Open Outlook.
  • Go to the affected profile.
  • Click Sign in via browser in the Outlook notification bar.
  • Sign in to your Gmail account again.

I’m eager to hear back and work together to find a solution.

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Answer 2

Error 0x800CCC0E with a Gmail inbox in classic (old) Outlook is a known issue related to Gmail/IMAP connectivity in classic Outlook, while the same account continues to work in New Outlook.

Use these steps in order:

1. Confirm Outlook build and known issue

• Classic Outlook currently has an investigated issue where users get 0x800CCC0E/0x800CCC0F synchronizing Gmail accounts.
• Make sure classic Outlook is fully updated. If the issue persists even on the latest build, it is likely this known issue and not a local profile problem.

2. Re‑authorize Gmail access for classic Outlook

• In classic Outlook, if an error dialog offers a Retry or Sign in via browser option for the Gmail account, select it.
• In the browser sign‑in page for Google, ensure the permission box is checked for:
  • “Read, compose, send, and permanently delete all your email from Gmail.” under Microsoft apps & services.
• Complete sign‑in and let Outlook resync. Missing this permission is a documented cause of sync failures and 0x800CCC0E for Gmail in classic Outlook.

3. If the Retry/sign‑in flow is not available or fails

• Remove the Gmail account from the classic Outlook profile.
• Add the Gmail account again via File > Add account and complete the browser sign‑in, again making sure the Microsoft apps & services Gmail permission is checked.

4. If classic Outlook still fails while New Outlook works

• Treat this as the ongoing Gmail/Yahoo sync issue in classic Outlook (0x800CCC0E/0x800CCC0F) that is under investigation.
• Continue using New Outlook for reliable Gmail access until a fix is released for classic Outlook in the affected builds.

If the problem extends to other non‑Gmail accounts in classic Outlook, run the Inbox Repair Tool on the PST/OST file as described in the referenced article, but for a Gmail‑only issue that works in New Outlook, the Gmail/IMAP connectivity issue in classic Outlook is the primary cause.

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References:

• Unable to add a Gmail account to classic Outlook
• Unable to sign in or add a Gmail account to classic Outlook
• I can't send or receive messages in Outlook
• Fixes or workarounds for recent issues in classic Outlook for Windows