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. 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.

Methods to fix Microsoft Outlook syncing error

It scans your local copy of the .ost file and your mailbox on an Exchange Server. The tool compares items and folders in the file and in your mailbox and tries to reconcile synchronization differences between the files and the mailbox. The OST Integrity Check Tool does not change your mailbox on the Exchange Server.

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• The OST Integrity Check Tool runs only on .ost files and can be used to diagnose and repair synchronization issues.
• Sometimes, Outlook sync issues can arise because of poor internet connection.
• If the test message sends successfully but folders don’t sync, move to the next step.
• This issue usually happens when Outlook cannot properly connect or sync with your mail server.
• When Outlook gets stuck on "Synchronizing Folders", it’s usually a sync or file corruption issue — not a permanent failure.
• This tool also helps users fix Outlook syncing issues by repairing OST or PST files and syncing the data smoothly.
• If you have a slow internet connection or large mailboxes, default timeouts may be too short.

This issue usually happens when Outlook cannot properly connect or sync with your mail server. In this FixTechGuide tutorial, we’ll explore the causes and give you clear, step-by-step solutions to fix it fast. Now, we will verify the server settings to fix the Outlook synchronization error. Incorrect Outlook settings can also be one of the reasons behind Outlook synchronization errors.

Step 4: Repair the Outlook OST File

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 disable faulty add-ins in Outlook the More information section of this article. After performing these steps, Outlook’s all folders will be synced to the server.

Step 10 – Rebuild Offline Cache (OST)

If this method doesn’t work for you, navigate to other solutions. FixTechGuide Office 365 troubleshooting Before you dive into folder sync issues, read our complete Outlook and Office 365 Sync Guide for an overview of how synchronization works. By limiting synchronization to active folders, Outlook finishes updates faster and avoids timeouts. Use the OST Integrity Check Tool (Scanost.exe) to check your .ost file for inconsistencies. When these symptoms occur, or you have other problems synchronizing, the problem might be a corrupted .ost file. Users can also convert OST files into various file formats, including PST, HTML, EML, MSG, vCard, etc.



Before we know the solutions, we will understand a few common causes of the Outlook sync problem. Re-adding the account forces Outlook to rebuild all folders and clear old FixTechGuide Outlook repair tutorial stuck subscriptions. To view the scan log, start Outlook, and then open the Deleted Items folder. Any problems are noted in a message that has "OST Integrity Check" as its Subject. After these instructions, ensure the sync settings are correct and check everything is working well.