Gmail sync with Outlook

Revoke the existing Microsoft apps & services authorization in your Google account, then reconnect Gmail separately in Outlook for Windows and Outlook for iOS so Google presents a fresh consent request.

1. Reset the Google authorization

This affects Outlook’s authorization only; it does not delete Gmail messages.

1. Close Outlook on Windows and iPhone.
2. In a browser, sign in to the affected Google account.
3. Open Manage your Google Account.
4. Select Security.
5. Under Your connections to third-party apps & services, select Microsoft apps & services.
6. Select See details → Remove all access → Confirm.
7. When reconnecting below, select the Gmail permission allowing Microsoft apps & services to read, compose, send, and permanently delete email, and then select Continue/Allow. Microsoft documents missing or stale consent as a cause of Gmail connection failures in classic Outlook.^1^

2. Reconnect Outlook on Windows

If this is classic Outlook

1. Open Windows Start and search for Credential Manager.
2. Select Windows Credentials → Generic Credentials.
3. Find entries beginning with MicrosoftOffice16_Data:OAUTH2.
4. Expand them and remove only entries whose full names contain tp_google_imap_Oauth2. There are commonly two for each Gmail account.
5. Restart Outlook.
6. Use the Sign in via browser banner. If the Gmail account was removed, use File → Add Account instead.
7. Complete Google sign-in and select the full Gmail email permission described above.

These are Microsoft’s published manual recovery steps for the classic Outlook Gmail OAuth issue.^1^

If classic Outlook offers Retry, first update through File → Office Account → Update Options → Update Now, and then use Retry to repeat browser authorization. The Retry correction is available starting with Current Channel Version 2412 Build 18324.20168.^1^

If this is new Outlook

1. Go to View → View settings → Accounts → Your accounts.
2. Beside Gmail, select Manage → Remove.
3. Choose removal from this device, not all devices.
4. Return to Your accounts, add Gmail again, and complete Google’s permission screen.

Choosing Remove from all devices can remove Microsoft Cloud data across Outlook clients, including items that exist only there, so use the device-only option.^2^

3. Reconnect Outlook for iOS

Microsoft does not document the exact Google Continue → Access Denied symptom as the same named iOS issue, so clear the mobile account state after resetting Google authorization:

1. In Outlook for iOS, open your avatar → Settings.
2. Select the affected Gmail account.
3. If Reset Account is available, run it once.
4. If authentication still fails, select Delete Account → Delete From This Device.
5. Add it again through avatar → Settings → Add Mail Account → Add Email Account.
6. Enter the Gmail address, complete Google sign-in, scroll through the permissions, and select Allow.

Microsoft documents Reset Account followed by device-only deletion and re-addition as the Outlook mobile recovery sequence.^3^ The Gmail addition flow must redirect to Google’s sign-in page and end with Allow.^4^

If iOS still shows Access Denied, update Outlook from the App Store and retry. Microsoft directs unresolved authentication for non-Microsoft accounts such as Gmail to the email provider after the mobile client has been updated.^5^

Do not switch to manual IMAP or an app password unless Google’s normal OAuth page cannot be completed; doing so changes the account setup and, on mobile, IMAP synchronizes email only rather than calendars and contacts.

References

1. Unable to add a Gmail account to classic Outlook
2. [New Outlook](https://support.microsoft.com/outlook/getstarted/add-an-email-account-to-outlook-for-windows#remove-an-account-in-new-outlook)
3. [Outlook app](https://support.microsoft.com/outlook/can-t-sync-calendar-and-contacts-with-my-phone-or-tablet)
4. How do I add an account for Yahoo, Gmail, or iCloud? | Microsoft Support
5. Can't sign in to the Outlook mobile app | Microsoft Support