Desktop Outlook no longer syncs with gmail unless I close outlook and restart

Linda 0 Reputation points
2025-12-10T06:56:22.9966667+00:00

I have been using desktop version of Outlook on my Windows 11 PC for years and beginning 2 days ago Outlook no longer syncs with my gmail account and when I send emails they sit in the outbox. If I restart Outlook the mail in the outbox sends and new emails show up (but just at the new startup). I have deleted my .ost file, set up a new profile, ran the quick repair and advanced repair in Outlook. I disabled ad-ins, turned off the firewall. Nothing works. Any ideas??

Outlook | Windows | Classic Outlook for Windows | For home
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  1. Q&A Assist
    2025-12-10T06:56:32.3233333+00:00
    AI generated content. This question contains an answer created with AI from Q&A Assist. Learn more

    It sounds like you're experiencing a frustrating issue with Outlook not syncing properly with your Gmail account. Since you've already tried several troubleshooting steps like deleting the .ost file, creating a new profile, and running repairs, here are a couple of additional suggestions that might help:

    1. Check for Updates: Ensure that your Outlook and Windows are fully updated. Sometimes, updates contain fixes for known issues.
    2. Disable Cached Exchange Mode: If you're using Cached Exchange Mode, try disabling it. Go to File > Account Settings > Account Settings, select your account, click on Change, and uncheck the Use Cached Exchange Mode option. Restart Outlook to see if this resolves the issue.
    3. Review Sync Issues: Check the Sync Issues folder in Outlook for any error messages that might indicate why syncing is failing. You can find this folder in the folder list.
    4. Network Connection: Ensure that your internet connection is stable. Sometimes, intermittent connectivity can cause syncing issues.
    5. Re-add the Gmail Account: Remove your Gmail account from Outlook and then re-add it. This can sometimes resolve persistent syncing issues.

    If none of these steps work, you may want to consider contacting Microsoft Support for further assistance.


    References:

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  2. Linda 0 Reputation points
    2025-12-10T07:18:41.3933333+00:00

    Both Outlook and Windows are fully updated.

    I do not have the "Use Cached Exchange Mode" option in my account settings?

    I was not familiar with the Sync Issues Folder. There are over 100,000 logs in this folder and many have sync errors noted.

    My internet connection is stable.


  3. Linda 0 Reputation points
    2025-12-10T08:00:35.2733333+00:00

    Some of the error messages in the sync log state "Error synchronizing message "Merry Christmas". I don't know where this comes from?

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  4. Marcelo Mendoza 5,645 Reputation points Independent Advisor
    2025-12-10T09:03:34.5233333+00:00

    Hello Linda,

    Thank you for sharing the details of what you have already tried and I understand how inconvenient it is when Outlook stops syncing with Gmail after years of working smoothly. I can see the effort you have put in by repairing Outlook, recreating profiles, and checking your connection and I know how frustrating it must feel to still see emails stuck in the outbox. Based on the sync errors and the large number of logs you mentioned the issue may be related to the way Outlook is communicating with Gmail’s IMAP servers. A good next step is to remove the Gmail account completely from Outlook and re-add it using the secure OAuth2 authentication method which ensures proper syncing with Google’s updated security requirements.

    You can do this by going to File, Account Settings, choosing your Gmail account, removing it and then adding it back by selecting Google as the account type so Outlook can prompt you to sign in through the Google authentication window. This refreshes the connection and clears out any corrupted sync relationships that may be causing the errors you are seeing.

    Have you noticed if the sync errors are tied to specific folders or messages or do they appear across all mail items?

    I hope this answer is helpful if you have further questions feel free to reply back

    Regards,

    Marcelo


  5. Marcelo Mendoza 5,645 Reputation points Independent Advisor
    2025-12-11T14:13:22.61+00:00

    Hi Linda,

    This issue is happening because Google recently tightened security for IMAP connections and Outlook sometimes fails to refresh the OAuth token correctly. That’s why syncing works right after you restart Outlook but then stalls it’s a common problem after recent updates to Outlook or Windows.

    To resolve this first make sure Outlook is fully updated because Microsoft has released fixes for Gmail OAuth issues. If you use two-step verification in Gmail you’ll need to generate an App Password and use that when re-adding your account. When you add Gmail back select Google as the account type so Outlook uses the secure sign-in window instead of basic authentication.

    It’s also helpful to clear any old credentials stored in Windows Credential Manager because corrupted tokens can cause sync failures. Remove entries related to mail.google.com or Outlook then restart Outlook and sign in again. In Gmail settings confirm that IMAP is enabled and disable auto-expunge if it’s turned on.

    If the problem persists try running Outlook in Safe Mode to rule out add-in conflicts. Restarting Outlook works temporarily because it forces a fresh OAuth token and IMAP handshake but fixing the token refresh issue will prevent the sync from stalling again.

    Best regards,

    Marcelo

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