Classic Outlook will not connect to Gmail

Question

I have used Classic Outlook to connect to my Gmail account for ages without any issues. Today, it fails to connect - although a connection to my wife's Gmail account works fine and they were set up identically.

I have tried deleting the account in Outlook and re-adding it (as a Google account) using the usual incoming and outgoing servers. Input port 993, output port 465 (and tried 587). Nothing works.

Can anyone help please?

Answer 1

Classic Outlook currently has known issues connecting to Gmail that match this scenario.

For a single Gmail account that suddenly stopped working while others still work, the most likely causes and fixes from current guidance are:

1. Outlook build and Google sign-in permissions
   • Recent Outlook builds require that, during the Google browser sign-in, the permission box is checked for: “Read, compose, send, and permanently delete all your email from Gmail.” under Microsoft apps & services.
   • If this was not granted for this specific Gmail account, Outlook can no longer connect while other Gmail accounts (like the wife’s) continue to work.
   Resolution (if on a fixed Outlook build – Current Channel Version 2412 Build 18324.20168 or later):
   • When the error appears in Outlook for that Gmail account, use the Retry link in the error window.
   • This re-opens the Google sign-in in the browser.
   • During sign-in, ensure the checkbox for Microsoft apps & services can access: “Read, compose, send, and permanently delete all your email from Gmail.” is selected.
2. Manual workaround if Retry does not work If the Retry flow is not available or does not fix the issue, use the manual workaround for that Gmail account: Step 1 – Remove Microsoft apps & services access in the Google account
   1. Close Outlook.
   2. Sign in to the affected Google account at https://www.google.com.
   3. Select the profile picture → Manage your Google Account.
   4. Go to Security.
   5. Under Your connections to third-party apps & services, select Microsoft apps & services.
   6. Select See Details for Microsoft apps & services has some access to your Google Account.
   7. Under Access you've given to Microsoft apps & services, select Remove all access and confirm.
   Step 2 – Remove the stored Google IMAP OAuth credentials in Windows
   1. Open Credential Manager from the Start menu (on some systems via Control Panel → Credential Manager).
   2. Select Windows Credentials.
   3. Under Generic Credentials, find entries starting with MicrosoftOffice16_Data:OAUTH2.
   4. Expand each and hover over the name until the full name including tp_google_imap_Oauth2 is visible; these correspond to Gmail accounts.
   5. Remove both credentials for the affected Gmail account (there are two per Gmail account).
      • To avoid removing credentials for other Gmail accounts, map them using the registry key: Computer\HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Identity\Identities The leading number in each identity key matches the credential in Credential Manager.
   Step 3 – Re-add or re-sign-in to the Gmail account in Outlook
   • Reopen Outlook.
   • If the account is still in the profile and shows a “Sign in via browser” bar, use that and sign in again, ensuring the Microsoft apps & services permission box is checked.
   • If the account was removed, use File → Add account to add the Gmail account again and complete the browser sign-in, again checking the permission box.
3. Other Gmail-specific causes
   • If the error shown is “We weren’t able to set up your Google account with IMAP. You may need to make changes to your Gmail settings.” and the above steps do not apply, verify that IMAP is enabled in the Gmail account settings (Google is gradually removing this control, but it still exists for some users). Google’s article Add Gmail to another email client explains how to check this.

These steps specifically address the current Gmail/Outlook classic connection failures where one Gmail account stops working while others continue to function.

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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
• gmail accounts no longer working in outlook classic - Microsoft Q&A
• search for solutions another user has found - Microsoft Q&A