How Can I Troubleshoot Microsoft Outlook Not Syncing Emails in Windows 11?

Because the messages already appear in Outlook on the web, first force a desktop synchronization and check whether Classic Outlook is offline before testing add-ins, repairing the profile, or creating a replacement profile.

1. Determine whether Outlook is failing to sync or only failing to refresh the Inbox

1. In Classic Outlook, inspect the status bar at the bottom.
   • If it says Working Offline, Disconnected, or Trying to connect, select Send/Receive → Work Offline to return online.
   • If it says Connected or All folders are up to date, continue below. ^1^
2. Press F9, or select Send/Receive → Send/Receive All Folders.
3. If only one account is affected, select Send/Receive → Send/Receive Groups, point to that account, and select Inbox. ^2^
4. Record any error code shown in Send/Receive Progress.
5. Clear any Inbox filter and check whether the missing message appears in search. If search finds it but the normal Inbox does not, this points toward a folder-view refresh/display problem rather than missing mail.

Do not repeat the Internet or restart tests; those have already been ruled out.

2. Validate the account configuration

Open File → Account Settings → Account Settings → Email, select the affected account, and identify its type.

• For POP or IMAP, compare the incoming and outgoing settings with those supplied by the email provider.
• A Hotmail.com or Live.com account should be configured as Outlook.com, rather than Exchange or Microsoft 365. An incorrect account type can prevent existing messages and folders from synchronizing correctly. ^3^
• If the email password was recently changed at the provider, update the stored Outlook credentials.

Gmail or Yahoo only: If Classic Outlook reports 0x800CCC0E or 0x800CCC0F, refresh its OAuth credentials:

1. Close Outlook.
2. Open Start → Credential Manager → Windows Credentials.
3. Under Generic Credentials, find entries beginning with MicrosoftOffice16_Data:OAUTH2.
4. Remove only the credentials belonging to the affected Gmail or Yahoo account.
5. Start Outlook, sign in again, and then restart Outlook once more if synchronization does not begin immediately.

This conditional workaround forces Outlook to request fresh credentials and does not remove the account. ^4^

3. Isolate add-ins

Press Windows+R, enter:

outlook.exe /safe

Test synchronization in safe mode. If it works there:

1. Open File → Options → Add-ins.
2. Next to Manage: COM Add-ins, select Go.
3. Take a screenshot of the enabled add-ins, then clear their check boxes—do not select Remove.
4. Restart normally and re-enable one add-in at a time, restarting Outlook after each, until the problem returns. ^5^

4. Repair or test a new profile without deleting the old one

First try File → Account Settings → Account Settings → Email → select the account → Repair, complete the wizard, and test again. The Repair option is unavailable for Outlook 2016 connected to Exchange. ^6^

If that fails, create a separate test profile:

1. Hold Shift while starting Outlook.
2. Select Options → Prompt a profile to be used → New.
3. Name the profile, add the affected account, and open Outlook with it.
4. Allow synchronization to complete and check for the missing messages.

Keep the original profile until the new one is confirmed working; creating another profile does not require deleting the existing one. ^7^

5. Repair local data only when corruption is suspected

If Outlook reports that it cannot open a data file or folders, close Outlook and run SCANPST.EXE against the affected .pst. Back up the file first; the tool creates a repair backup, but severely corrupted items might not be recoverable. For an Exchange account, Microsoft documents that an offline .ost can be recreated from the server. ^8^

For locally stored POP mail or archives, create an additional backup through File → Open & Export → Import/Export → Export to a file → Outlook Data File (.pst) before changing profiles or repairing data. ^9^

If the new profile also fails while Outlook on the web remains current, use Microsoft’s Classic Outlook troubleshooter or contact support; that result makes a simple profile-corruption explanation less likely. ^10^

References

1. Classic Outlook(#tab/classic-outlook)
2. Sync to manually check for new mail and to send messages in Outlook | Microsoft Support
3. Troubleshoot Outlook email setup | Microsoft Support
4. Users get errors 0x800CCC0E & 0x800CCC0F synchronizing Gmail and Yahoo accounts in classic Outlook | Microsoft Support
5. Classic Outlook(#tab/classic-outlook)
6. Fix your Outlook email connection by repairing your profile
7. Create a profile in classic Outlook for Windows
8. Repair Outlook Data Files (.pst and .ost)
9. Back up your Outlook email | Microsoft Support
10. Issues sending and receiving email | Microsoft Support