Gmail loading on outlook

Update classic Outlook first, then repeat the browser-based Google authorization and grant the requested Gmail permission; this addresses the repeated sign-in flow that is ending at the outlook.office.com HTTP 500 page.

1. Update Outlook and retry Google sign-in

1. In Outlook, select File > Office Account.
2. Select Update Options > Update Now.
3. When the update finishes, restart Outlook.
4. When Outlook requests Google authentication, choose Sign in via browser or Retry.
5. Sign in with the affected Gmail address.
6. On Google’s permissions page:
   • Select Allow.
   • If shown, check “Read, compose, send, and permanently delete all your email from Gmail.”
7. Return to Outlook and allow synchronization to finish.

Microsoft fixed an earlier classic Outlook Gmail browser-sign-in problem in Current Channel Version 2404 Build 17531.10000. A newer Retry workflow is available for Microsoft 365 Current Channel Version 2412 Build 18324.20168 and later.^1^^2^

Check the installed version under File > Office Account > About Outlook. If Update Options is unavailable, the Office installation may be managed or use a different update mechanism.

2. If the sign-in loop continues, reset the saved authorization

For Outlook for Microsoft 365, Microsoft documents the following manual workaround. This signs Outlook out of Gmail but does not delete messages stored in Gmail.

1. Close Outlook.
2. Open your Google Account in a browser.
3. Select Manage your Google Account > Security.
4. Under Your connections to third-party apps & services, open Microsoft apps & services.
5. Select See details > Remove all access > Confirm.
6. In Windows, open Start, search for Credential Manager, and open it.
7. Select Windows Credentials.
8. Under Generic Credentials, find entries beginning with: MicrosoftOffice16_Data:OAUTH2
9. Expand or hover over each entry and identify those containing: tp_google_imap_Oauth2
10. Remove both OAuth credentials associated with the affected Gmail account.
11. Reopen Outlook and select Sign in via browser.
12. Complete Google sign-in and grant the full Gmail permission requested.

These are Microsoft’s documented steps for clearing the existing Google authorization and cached Windows OAuth credentials before rebuilding the browser connection.^2^

Avoid deleting unrelated credentials. If several Gmail accounts are configured and the entries cannot be distinguished safely, stop before removing them and use a new Outlook profile instead.

3. If Outlook still returns HTTP 500

Create a separate Outlook profile to determine whether the existing profile contains damaged or stale sign-in state:

1. Close Outlook.
2. Open Control Panel and search for Mail.
3. Select Mail > Show Profiles > Add.
4. Name the profile and add the Gmail account.
5. Complete the browser-based Google sign-in and select Allow.
6. Start Outlook with the new profile and test Gmail.

If the new profile works, keep it and add any other required accounts. If the new profile also reaches the same outlook.office.com HTTP 500 page, check Microsoft’s current classic Outlook known-issues list and contact Microsoft Support with:

• Outlook edition, version, and build from File > Office Account > About Outlook
• Windows version
• The exact HTTP 500 text
• The approximate failure time and time zone
• Confirmation that Gmail still works on the phone and directly in a browser

Microsoft maintains the current fixes and workarounds for classic Outlook separately.^3^

References

1. Unable to sign in or add a Gmail account to classic Outlook | Microsoft Support
2. Unable to add a Gmail account to classic Outlook | Microsoft Support
3. Fixes or workarounds for recent issues in classic Outlook for Windows