It is a normal Outlook function, and these messages act as error-checking mechanisms for programs that use it for Troubleshoot Office 365 Sync and Login Issues 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 Office 365 sync problems and login fixes 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 FixTechGuide support for Office 365 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

In the main interface, you need to click on "Select PSF/OST file to repair" to upload the required file.

• 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.
• Incorrect Outlook settings can also be one of the reasons behind Outlook synchronization errors.
• 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.
• However, serious problems might occur if you modify the registry incorrectly.
• 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.



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.