cannot add gmail account to outlook

Follow these steps to restore Gmail connectivity in classic Outlook on Windows:

1. Confirm Outlook is on a fixed build
   • The Gmail IMAP sign‑in issue is fixed starting with Current Channel Version 2412 Build 18324.20168.
   • In Outlook, select File > Office Account > About Outlook and verify the version/build.
   • If older, update Office, then retry adding the Gmail account.
2. Retry the Gmail consent flow (if prompted)
   • When adding the Gmail account, if an error dialog appears, select the Retry link.
   • 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.”
   • Complete sign‑in and let Outlook finish the setup.
3. If it still fails, use the manual workaround Step 1 – Remove Microsoft Apps & Services access in Gmail
   1. Close Outlook.
   2. Sign in to the Google account at 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.
   8. Confirm.
   Step 2 – Clear stored Google IMAP credentials in Windows
   1. Open Credential Manager from the Start menu (in Windows 10, via Control Panel if needed).
   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 value shows tp_google_imap_Oauth2.
   5. Remove each credential that includes MicrosoftOffice16_Data:OAUTH2 (there are typically two per Gmail account).
   6. Close Credential Manager.
4. Re‑add the Gmail account in Outlook
   • Start Outlook and add the Gmail account again.
   • When the Google sign‑in window opens, sign in and ensure the permission for “Read, compose, send, and permanently delete all your email from Gmail.” is selected.
5. If the error mentions IMAP settings or “app may not be secure”
   • Ensure IMAP is enabled in Gmail:
     1. Go to Gmail.com in a browser.
     2. Open Settings > Forwarding and POP/IMAP.
     3. Under IMAP Access, select Enable IMAP and Save Changes.
   • Then retry adding the account in Outlook.

If Outlook is on a supported build, IMAP is enabled, the Google consent is granted with full email access, and the old OAuth2 credentials are removed, the Gmail account should connect to the IMAP server and resume receiving mail.

References:

• Unable to add a Gmail account to classic Outlook
• Unable to sign in or add a Gmail account to classic Outlook
• Fix problems connecting your Google account to the Microsoft Cloud