It is a normal Outlook function, and these messages act as error-checking mechanisms for programs that use it for Fix Outlook and Office 365 Errors 2025 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

This blog talks about the causes behind Outlook synchronization errors and a few solutions to fix Outlook sync issues. We have shared five manual methods in this blog to resolve the Outlook syncing errors. mailbox not updating on IMAP Apart from this, we also discuss the Shoviv OST to PST Converter Tool, a professional way to repair, recover, and convert Outlook data files. This solution will be beneficial for users who are facing Outlook syncing issues because of corrupted PST or OST files.

Solution 7: Create a New Profile

While synchronizing your Outlook with the Exchange server, sometimes you receive error messages. It leads to the occurrence of the issues of Outlook OST synchronization. In such scenarios, you need to check the proper working of the synchronization process. After rebuilding the Outlook data file (OST), you must check for any missing mailbox items. After the conversion, you can import the PST into your newly created Outlook account via the Import Export wizard. The software can also directly export the OST file data to an existing Outlook profile, live Exchange Server, or Microsoft 365.

Solution 8: Rebuild Outlook Data File (OST)

After you make this change, none of the shared folders in the secondary mailbox will be available to you in Outlook when you're working offline. However, all folders in the primary mailbox will still be available to you when you're working offline. Conflicts with antivirus disable faulty add-ins in Outlook software or firewall can impact Outlook's synchronization process. You can temporarily turn off your antivirus software and firewall.

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.

How to repair errors by using Scanost.exe

• The OST Integrity Check Tool (Scanost.exe) is installed when you install Outlook in the following locations, as appropriate for the Outlook version that you are running.
• The tool does not interact with your mailbox on the Exchange Server.
• 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.
• For more information, see the More information section of this article.
• Follow each step carefully to resolve synchronization errors.
• So, follow the below steps to reset Microsoft Outlook settings.

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.