My Office 365 Outlook is not syncing with my Gmail account

Question

My Office 365 Outlook application is not syncing with my Gmail account. It worked just fine Saturday, March 14th, but as of today, March 17th, it is not working. I am able to log in to my Gmail account through Google. IMAP is enabled on my Gmail account and I am on the latest version of 365.

Answer 1

Hello,

The AI answer got a bulk of it, but misses some key step like registry edit.

Please use the workaround 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

Follow these steps to restore syncing between Outlook (Microsoft 365) and Gmail:

1. Confirm IMAP is enabled in Gmail
   Even if IMAP was already enabled, recheck it:
   1. Sign in to Gmail in a browser.
   2. Select the gear icon > Settings.
   3. Go to Forwarding and POP/IMAP.
   4. Under IMAP access, make sure Enable IMAP is selected.
   5. Select Save Changes.
2. Verify Outlook is on a fixed build
   Recent issues with Gmail sign-in and sync in classic Outlook have been fixed in newer builds.
   1. In Outlook, go to File > Office Account.
   2. Check the version/build.
   3. If the build is older than the fixed versions (for example, Current Channel Version 2404 or later for Gmail sign-in fixes, or Version 2412 Build 18324.20168 for the Retry behavior), select Update Options > Update Now to update Office.
3. Re-run the Google consent (classic Outlook)
   If the Gmail account was added earlier and the consent for Microsoft apps & services was incomplete, Outlook can lose access:
   • When Outlook shows an error for the Gmail account, use the Retry link in the error window.
   • In the browser sign-in that opens, sign in to Google and ensure the box is checked for:
     “Read, compose, send, and permanently delete all your email from Gmail.”
   • Complete the flow and return to Outlook, then test Send/Receive.
4. Check for the “app not secure / IMAP” error path
   If Outlook shows messages like:
   • “The browser or app may not be secure.” or
   • “We weren’t able to set up your Google account with IMAP. You may need to make changes to your Gmail settings.”
     then:
   • Make sure IMAP is enabled in Gmail (step 1).
   • Ensure Outlook is updated to a build that uses the new browser-based sign-in (for example, Current Channel Version 2404 or later).
     After updating, restart Outlook and try Send/Receive or remove and re-add the Gmail account.
5. If Outlook shows “Could not sign you in to Google – IMAP”
   On older builds, adding Gmail could fail with:
   “Sorry, we could not sign you in to Google – IMAP. Please try again later.”
   If still on such a build and an update is not yet available in the channel:
   1. Open Outlook or another Office app.
   2. Go to File > Office Account.
   3. Under Account Privacy, choose Manage Settings.
   4. Check Enable optional connected experiences.
   5. Restart Outlook and test the Gmail account again.
6. If still failing, remove and re-add the Gmail account
   After confirming IMAP is enabled and Outlook is updated:
   1. In Outlook, go to File > Account Settings > Account Settings.
   2. Select the Gmail account and choose Remove.
   3. Restart Outlook.
   4. Add the Gmail account again from File > Add Account, and complete the Google sign-in, ensuring the full email permission is granted.

If these steps are followed (IMAP enabled, Outlook updated to a fixed build, Google consent re-done, and account re-added if needed), Gmail should resume syncing with Outlook.

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References:

• Fix problems connecting your Google account to the Microsoft Cloud
• Prepare your Gmail or Google Workspace (formerly G Suite) account for connecting to Outlook and Microsoft 365 or Office 365
• Unable to sign in or add a Gmail account to classic Outlook
• Unable to add a Gmail account to classic Outlook
• Unable to add a Gmail account to Outlook "Could not sign you in to Google"