error when adding new gmail to outlook 365 classic

Question

Getting error "We weren't able to set up your Google Account with IMAP. You may need to make changes to your Gmail settings." when adding new account to outlook 365 classic. Previously tried various solutions posted in google search and ChatGpt.

Answer 1

Hi Nick Vasilenko,

Welcome to the Microsoft Q&A forum.

I understand how frustrating it can be to run into an error when adding a Gmail account to Outlook for Windows (classic), especially when the setup does not complete successfully.

I see that there is already a Q&A Assist answer above, and the guidance provided there is generally accurate for this scenario. May I ask if you have had a chance to try those steps, particularly the checks related to Gmail sign‑in and re‑adding the account after clearing any existing credentials?

To add a bit more information, Microsoft has also documented a related sign-in/setup scenario for Gmail in classic Outlook (for example, messages like “We weren’t able to set up your Google account with IMAP” or “The browser or app may not be secure”) and notes that updating Outlook to a build that includes the fix can resolve it. Reference: Unable to sign in or add a Gmail account to classic Outlook - Microsoft Support

If you would like an additional official option to narrow this down, you can run the built-in troubleshooters for classic Outlook (profile, authentication, connectivity) using the Windows Get Help app: Classic Outlook troubleshooters - Microsoft Support

Since this is a user-to-user forum, contributors can help validate the correct setup path and point you to the right official guidance, but do not have access to account-side diagnostics. If you have already tried the Q&A Assist steps and the Microsoft workaround above and still get the same error, contacting Microsoft Support would be the next step.

I hope this clarification helps explain what is happening and how the Q&A Assist guidance fits into the overall setup process.

Answer 2

Follow these steps in classic Outlook for Windows to resolve the IMAP error when adding a new Gmail account.

1. Make sure Outlook has the Gmail fix

• The IMAP/Gmail sign-in issue is fixed in newer Outlook builds.
• Update Outlook: File > Office Account > Update Options > Update Now.
• For the error “We weren’t able to set up your Google account with IMAP…”, the fix is available starting in Current Channel Version 2404 (Build 17531.10000) and later.

2. Confirm IMAP is enabled in Gmail

• In a browser, sign in to Gmail.
• Follow Google’s guidance in Add Gmail to another email client to verify IMAP is turned on (if the IMAP setting still appears in your account).
• If IMAP is off, turn it on and save changes.

3. Re-run the Gmail consent correctly (classic Outlook Gmail fix) If the error appears after sign-in, the cause is often missing consent for Microsoft apps & services:

• In Outlook, add the Gmail account again.
• When the Google sign-in page opens in the browser, after entering the Gmail address and password, on the permissions page ensure the option is checked:
  • “Read, compose, send, and permanently delete all your email from Gmail.” under Select what Microsoft apps & services can access.
• Complete the sign-in.

If the account is already added but not syncing, and Outlook is on Current Channel Version 2412 Build 18324.20168 or later:

• When the error dialog appears, select the Retry link.
• This re-opens the browser sign-in so the permission box above can be checked.

4. If the Retry path does not work: use the manual workaround Follow the manual workaround to clear the old Google/Outlook connection and credentials, then add the account again.

Step 1 – Remove Microsoft apps & services access in Google

1. Close Outlook.
2. In a browser, go to https://www.google.com and sign in with the affected Gmail account.
3. Select the profile picture > Manage your Google Account.
4. Select Security on the left.
5. Scroll to Your connections to third-party apps & services and select Microsoft apps & services.
6. Under Microsoft apps & services has some access to your Google Account, select See Details.
7. Under Access you've given to Microsoft apps & services, select Remove all access.
8. Select Confirm.

Step 2 – Delete Google IMAP credentials from Windows Credential Manager

1. From the Windows Start menu, search for Credential Manager and open it (on Windows 10, open 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 MicrosoftOffice16_Data:OAUTH2 to see the full name including tp_google_imap_Oauth2 (these are the Gmail IMAP credentials).
5. Remove each credential that includes tp_google_imap_Oauth2. There are two per Gmail account; remove both.
   • To target only one Gmail account, map credentials to identities using the registry key:
     • Computer\HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Common\Identity\Identities

Step 3 – Add the Gmail account again in Outlook

1. Open Outlook.
2. Go to File > Add Account.
3. Enter the Gmail address and continue.
4. When the Google sign-in window opens in the browser, sign in and on the permissions screen ensure the box for “Read, compose, send, and permanently delete all your email from Gmail.” is checked.
5. Complete sign-in and let Outlook finish the setup.
6. If automatic setup still fails

• For some third-party accounts, an app password or manual setup may be required.
• In classic Outlook: File > Add Account > enter email > Advanced options > Let me set up my account manually > choose IMAP.
• Use the IMAP/SMTP server names and ports provided by Gmail or from the POP/IMAP reference, then connect.

If these steps are followed in order (update Outlook, verify IMAP in Gmail, clear old access/credentials, then re-add with the correct consent), the IMAP setup error for a new Gmail account in classic Outlook should be resolved.

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References:

• Unable to sign in or add a Gmail account to classic Outlook
• Unable to add a Gmail account to classic Outlook
• Troubleshoot Outlook email setup