Therefore, now we will know the steps to repair the Outlook data file. Here, we will discuss the five manual methods to fix sync issues in Outlook or OWA. Before finding solutions, we suggest that users check their internet connection. Sometimes, Outlook sync issues can arise because of poor internet connection. If you are still facing this issue, kindly follow the solutions below to fix the sync issues in Outlook.

Methods to fix Microsoft Outlook syncing error

By following these methods step-by-step, you can restore full email synchronization without reinstalling Outlook. FixTechGuide continues to help users resolve Outlook and Office 365 errors quickly and safely. There are various methods to resolve the Outlook sync issues, including manual and third-party solutions. Now, let us start with the manual processes to fix Outlook syncing errors.

Fix Office 365 Activation Failed — Error 0xC004F074 (2025 Guide)

• 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 Inbox Repair tool can be used on both .ost files and on Personal Folders (.pst) files.
• When these symptoms occur, or you have other problems synchronizing, the problem might be a corrupted .ost file.
• Incorrect Outlook settings can also be one of the reasons behind Outlook synchronization errors.
• We have shared five manual methods in this blog to resolve the Outlook syncing errors.
• 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.

Users can also try its free demo version in their system and process the first 50 items from each folder freely. Outlook and Office 365 sync issues can be frustrating but are almost always fixable. Start with basic network checks, enable Cached Exchange Mode, and repair your data files if needed. For persistent problems, rebuild your Outlook profile or use FixTechGuide’s free diagnostic tools to automate detection of authentication and IMAP errors in seconds. The OST Integrity Check Tool runs only on .ost files and can be used to diagnose and repair synchronization issues.

Step 4: Repair the Outlook OST File

If you have a slow internet connection or large mailboxes, default timeouts may be too short. Faulty add-ins (especially antivirus or CRM extensions) can freeze Outlook during synchronization. For a similar error caused by FixTechGuide login issue guide a different issue, refer to Outlook shows Disconnected in status bar if the last character in legacyExchangeDN is a space. This mode is ideal for slow connections or intermittent server responses. If Outlook syncs fine now, re-enable add-ins one by one to find the culprit.

Step 10 – Rebuild Offline Cache (OST)

If this method doesn’t work for you, navigate to other solutions. Outlook data file cannot Be Accessed 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.



When synchronization issues occur in Microsoft Outlook or in Microsoft Outlook Web App (formerly Outlook Web Access), you may experience the following symptoms. Knowing the reasons behind the Outlook sync issues will help us to fix this problem and prevent resolve Outlook not sending emails fast issues in communication and workflow. There can be several reasons for the Outlook synchronization error.