my outlook express has stopped synchoranizing with gmail and its showing error

Question

my outlook express has stopped synchoranizing with gmail and is showing an error all of the sudden. till yesterday everything was working but today it is not.

Answer 1

Any chance you meant Outlook Classic? Outlook Express is a legacy app that has been discontinued in 2006, so if it is not working, it is completely expected.

If it is Outlook Classic, many users seem to have this issue recently. It is a known issue. Microsoft is still investigating this issue. The current workaround is published here: https://support.microsoft.com/office/users-get-errors-0x800ccc0e-0x800ccc0f-synchronizing-gmail-and-yahoo-accounts-in-classic-outlook-e5a7b684-7c5c-4848-ab2d-d48291451f67

Answer 2

The issue is likely related to recent changes in how Gmail accounts authenticate and sync in classic Outlook/Outlook Express.

Use these steps to restore syncing:

1. Check Outlook/Office build and apply the Gmail fix
   Recent Outlook builds include a fix for Gmail sign-in and sync issues. Make sure Outlook (classic) is updated to a build that contains the fix described in the articles below. After updating, restart Outlook and try Send/Receive again.
2. Re‑authenticate the Gmail account in Outlook
   If the Gmail account was added previously, the Google permission may no longer be valid. Remove and re-add the Gmail account, or trigger the new sign-in flow:
   • In classic Outlook, go to File > Account Settings > Account Settings.
   • Select the Gmail account and choose Repair (or remove and re-add if Repair fails).
   • When the Google sign-in window opens in the browser, sign in to Gmail and on the permissions page make sure to check the box:

     “Read, compose, send, and permanently delete all your email from Gmail.”

   • Complete the sign-in and return to Outlook, then run Send/Receive.
3. If you see “We weren’t able to set up your Google account with IMAP”
   This error can occur if IMAP is disabled in Gmail for that account. Follow Google’s guidance in Add Gmail to another email client to confirm IMAP is enabled (if that setting is still present for the account), then repeat the add/repair steps above.
4. If Outlook says the browser/app is not secure
   Newer Outlook builds open a separate browser window for Google sign-in to address this. Ensure Outlook is on a channel/build that includes this fix (see the “STATUS: FIXED” section in the referenced article). If a temporary Insider channel was used as a workaround earlier, switch back to Current Channel after updating.

If, after updating and re‑authenticating with the correct Gmail permissions, sync still fails, remove the Gmail account from the Outlook profile and add it again from scratch using the modern Google sign-in flow, making sure the permission box above is selected.

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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