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. FixTechGuide mailbox repair steps 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)

The other solution to fix flush DNS and re-sync Outlook 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

Any problems are noted in a message that has "OST Integrity Check" as its Subject. 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. For more information about the maximum allowed share of server resources on Microsoft Exchange Server 2007, see A user is consuming their maximum allowed share of server.

How to repair errors by using Scanost.exe

• It leads to the occurrence of the issues of Outlook OST synchronization.
• We have given you complete information about the synchronization issues folders in Outlook, and the ways to solve it manually and automatically.
• You can see the synchronization status here and your new .ost file now.
• In the main interface, you need to click on "Select PSF/OST file to repair" to upload the required file.
• The Inbox Repair tool can be used on both .ost files and on Personal Folders (.pst) files.
• This tool also helps users fix Outlook syncing issues by repairing OST or PST files and syncing the data smoothly.
• You can try fixing it automatically with the Wondershare Repairit for Email.
• If users are facing syncing issues in Outlook due to corrupt Outlook data files, they must choose a professional tool, like Shoviv OST to PST Converter Tool.

If you see any mismatch in the data, then the methods discussed in this guide will surely help you resolve the issue. When you add other mailboxes to your Outlook profile and enable caching of the shared mailbox folders, Outlook individually registers every folder in each cached mailbox. Each of these registered folders counts toward the objtFolder type limit on the server that's running Exchange Server. Items and logs not synced to your email by Microsoft Outlook are present in the synchronization issues folders.



There can be several reasons for the Outlook synchronization error. Before we know the solutions, we will understand a few common causes of the Outlook sync problem. If disabling the software resolves the issue, then change your antivirus and firewall settings and add Outlook as an exception. Use the OST Integrity Check Tool (Scanost.exe) to check your .ost file for inconsistencies.