It is a normal Outlook function, and these messages act as error-checking mechanisms for programs that use it for send/receive Error 0x800CCC0E fix syncing email services. In this article, we will discuss the synchronization issues in folders, and the method to solve it manually and automatically with the excellent Outlook Repair software. If these methods do not resolve the issue, we recommend that you rebuild the .ost file. To do this, delete the .ost file, and then let Outlook download the information again from Exchange Server. For more information, see the More information section of this article.

Solution 4: Disable Antivirus and Firewall Temporarily

However, serious problems might occur if you modify the registry incorrectly. For protection, back up the registry before you modify it so that you can restore it if a problem occurs. For more information about how to back up and restore the registry, see How to back up and restore the registry in flush DNS and re-sync Outlook Windows. Now, we will verify the server settings to fix the Outlook synchronization error. The in-built Synchronization process happens when your OST or PST files get updated.

Solution 7: Create a New Profile

After trying all the methods, is the outlook error synchronizing folder not resolved? You can try fixing it automatically with the Wondershare Repairit for Email. As PST files are bigger and so chances of the getting corrupted are high.

Solution 8: Rebuild Outlook Data File (OST)

The other solution to fix Outlook Login Issues Troubleshooting Outlook sync issues is recreating Microsoft Outlook profile. Follow each step carefully to resolve synchronization errors. Are you finding mismatches in the messages received in Microsoft Outlook in comparison to its web app?

Solution 1: Update the Outlook Application

If you are still facing this issue, kindly follow the solutions below to fix the sync issues in Outlook. If you have problems when you try to open your .ost file, you can use the Inbox Repair tool (Scanpst.exe) to diagnose and repair errors in your .ost file. The Inbox Repair tool can be used on both .ost files and on Personal Folders (.pst) files. The Inbox Repair tool scans the .ost or .pst file and makes sure that the file structure is intact. The tool also tries to repair the internal data structures, if it is necessary. The tool does not interact with your mailbox on the Exchange Server.

• In order to determine the number of folders and subfolders that are in a mailbox or folder, run the Get-MailboxFolderStatistics cmdlet.
• Users can also try its free demo version in their system and process the first 50 items from each folder freely.
• As stated in the 9646 event that is shown in the "Symptoms" section, the default limit for objtFolder objects per mailbox is 500.
• Before finding solutions, we suggest that users check their internet connection.
• Once the file is selected, now click on the "Repair" and begin the repair process.

Incorrect Outlook settings can also be one of the reasons behind Outlook synchronization errors. So, follow the below steps to reset Microsoft Outlook settings. After the files get repaired, restart the Outlook program to ensure that the Outlook syncing issues are resolved or not. You can see the synchronization status here and your new .ost file now. As it is the replication of the existing information of Exchange Server mailbox, so the complete process does not cause any damage to the information. See your Exchange Server administrator for this information or permissions.



The OST Integrity Check Tool does not change your mailbox on the Exchange Server. The tool records any differences in a scan log so that you can see what differences the tool found and resolved. The scan log also identifies any situations that the tool could not resolve and that you must fix manually. There are various methods to resolve the Outlook sync issues, including manual and third-party solutions. Firstly, we will discuss a few manual methods to resolve this Outlook error and share the stepwise procedure of each method to successfully fix synchronization issues. Now, let us start with the manual processes to fix Outlook syncing errors.