Rebuild and Recover Damaged Offline OST File in Outlook

Updated On - January 31, 2023 by Nasir Khan |

Reading Time: 6 minutes

Corruption in OST file is a very common error in MS Outlook, it can be happened due to many reasons. Here in this blog, we read about the reasons and know, how to rebuild or recover damaged Offline OST file in Outlook.

About Outlook OST File

Outlook Offline Storage Table (OST) files allow to work even when Offline.OST is a replica of the mailbox data stored on the Exchange server. OST file is created on the local machine when you configure or sign in using a Microsoft Exchange, Microsoft Office 365, or IMAP account in MS Outlook.

OST files let users access, read, and draft messages even when the system is offline. All the changes done offline are synchronized with the Exchange Server when the system is connected to the Internet.

Corrupt Outlook OST File Error Messages

In Microsoft Outlook 2013 or later versions, you receive the following error message:

Errors have been detected in the file C:\Users<name>\AppData\Local\Microsoft\Outlook\

Recover damaged OST files

Most Common Reasons for Outlook OST File Corruption

Outlook OST file may get corrupt, damaged, or inaccessible due to unknown reasons such as:

  • Improper Termination of the application
  • Presence of Virus/Bugs in the system
  • Hardware-related issues
  • Sudden Power Failure
  • Oversized or large OST file
  • Corruption or bad sectors in the hard disk where OST file is saved
  • Incompatible third-party Outlook add-ins
  • Network issues during mailbox synchronization
  • Header File corruption
  • System crash
  • Disk errors
  • Force close ‘Not Responding’ MS Outlook
  • Internal structure issue
  • Data storage device failure
  • Corruption in file system
  • Storage limitations
  • Accidental deletion of Exchange mailbox
  • Inefficient synchronization or incorrect file system recovery

Symptoms that indicate issues with Outlook OST File

Below are few common symptoms that indicate issues with Outlook OST file:

  • Outlook takes long time to load/start
  • Delays in sending or receiving new emails
  • Issues with mailbox synchronization
  • Outlook crashes or freezes frequently

Manual Methods to recover damaged offline OST File

1st method: Recreate OST File

  • Open Control Panel.
  • Select Mail 2
  • Click Show Profiles. 3
  • Choose the profile name and click on Properties. 4
  • Click Email Accounts. 5
  • In Account Settings, select Data files, select the File Path.
  • Click Open File Location. 6
  • Delete the corrupted OST File.

A new file with the data of damaged OST is created.

2nd method: Use the built-in Outlook Inbox Repair Tool

Use the scanpst.exe utility of Outlook to repair OST File.

  1. Run the exe from where Outlook is present.
  2. Click Browse to locate the corrupted OST file. 7
  3. Click Start to begin repairing. 8
  4. Once scanning is completed, click Repair. 9
  5. On completion of repair process, a Repair Complete dialogue box appears. 10

3rd method: Launch Outlook in Safe Mode

Sometimes add-in can cause conflict. In safe mode they’re disabled. Use the command, outlook.exe/safe.


4th method: Disable Firewall & Anti-virus settings to Repair OST File

Turn off the antivirus program, and other firewall settings, as Outlook is programmed to scan and detects problems for every incoming and outgoing email. An enabled antivirus setting may block the normal working of MS Outlook at times, so you may need to disable the settings and restart the system to view the changes.

5th method: Update Folder

This manual method allows changing the properties of folder (to clear offline items) to repair corrupt, damaged or inaccessible Outlook OST File issues.

For MS Outlook 2010:

  1. Right-click the folder and click Properties.
  2. When the dialog box appears, click ‘Clear Offline Items’ option.
  3. Click Ok.
  4. Click Send/Receive option in Outlook.
  5. Click Update Folder to save the changes.

6th method: Compress the OST file

A large-sized Outlook OST file may lead to OST file corruption, sluggish Outlook performance, etc. The OST file items are stored in such a way that they may occupy additional space and be unusable for other purposes. On compacting the OST files, it reduces the extra space occupied by the OST files.


7th method: Turn-off Anti-Virus

Turning off anti-virus software helps in proper functioning of MS Outlook. The user can disable settings and restart Outlook to see the changes.

8th method: Turn off Compatibility Mode

  1. Navigate to the Start menu and type exe in the search bar.
  2. Once opened, right-click on the outlook.exe and select Properties.
  3. Click on the compatibility tab and clear the command i.e. ‘Run this program in compatibility mode for’ in the dialogue box. 13
  4. Click OK and restart your computer.

9th method: Set Outlook Profile via Auto Account Setup in Outlook

  1. Navigate to the Windows Control Panel and select Mail in options.
  2. In the dialog box that appears, select Show Profiles.
  3. In the next dialog box, click Add.
  4. Select New Profile and select the account type (be it Exchange account), click OK to proceed.
  5. On the Auto Account Setup page, enter your name, email id, and password linked to your mailbox.
  6. Click Next to continue.
  7. Outlook will start to configure your account. In the dialog box that appears, check the option ‘Don’t ask me about this website again’. Click Allow.
  8. A windows security dialog box appears – enter your username along with the password. Click OK.
  9. Once done, outlook will discover your email account and end the configuration process. Click Finish to end up configuration.

10th method: Recover Navigation Pane Configuration File

    1. Click on the Start menu.
    2. Select the Run command from the menu.
    3. Type the command i.e. outlook.exe /resetnavpane in the dialog box. 14
  1. Click OK and restart your device.

11th method: Fix Outlook hanging on Loading Profile

Step 1: Ending all the processes working in task manager

  1. Right-click on the taskbar and click on Task Manager.
  2. In the tab of Processes, select all the office processes working.
  3. For each process, click on End Task and repeat it for every enlisted process.

Step 2: Disable all the outlook presence features

  1. Launch Outlook. In the main menu, select Files > click Options > click People.
  2. Uncheck all the checkboxes i.e. display online status next to the name and show user photographs when available.
  3. Once done with unchecking all boxes, click OK and restart Outlook application.

Limitations of manual methods

  • Manual method of repairing damaged Outlook OST files only fixes minor errors.
  • There is no guarantee of data safety and chances of data loss.
  • The inbuilt tool is unavailable in Outlook 2010, 2013 or later versions.
  • There is a size limitation while repairing the damaged OST files using manual methods. The manual method supports repairing damaged OST files only up to 2gb size.
  • Sound technical knowledge is required.
  • High risk of human errors.
  • The manual process of repairing damaged OST files is slow.
  • Manual process cannot repair encrypted OST files.

Third-party Professional OST File Recovery Software

Regain OST Recovery tool is professional third-party software to recover corrupt, damaged or inaccessible Outlook OST files. The tool effectively recovers mailbox data from Outlook OST files and saves them in PST file. The tool recovers deleted emails, calendar events, contacts, notes, tasks, appointments, journals, etc. from OST files and allows saving the recovered data in PST, EML, MSG, MBOX, vCard, and HTML file formats.

Free Download100% Secure Buy NowPrice: $39

Eminent Features of OST File Recovery Tool

  • Allows exporting OST file to office 365 accounts or Live Exchange Server.
  • Repairs password-protected OST files.
  • Displays preview of recovered email items before saving.
  • No file size limit to recover damaged OST file.
  • Maintains metadata, formatting, structure of OST file.
  • Offers an easy-to-use, self-descriptive graphical user interface.
  • Compatible with all versions of MS Outlook and Windows operating systems.
  • Available as a free to download demo version.

This article discusses the manual methods for repairing and recovering damaged, inaccessible or corrupt Outlook OST files. Since a manual method has some limitations, we recommend using a professional third-party OST File Recovery tool for effectively recovering mailbox data from OST files. You can also check the capabilities of the tool by downloading a free trial version.

Author: Nasir Khan

I am Nasir Khan from India, working as a Content Developer in Regain Software. Here I am writing about our products and their updates. And writing some free solutions from converting emails or Cloud Migration process. We have tools like Email Converter, Emails backup and Cloud migration.

One thought on “Rebuild and Recover Damaged Offline OST File in Outlook”

  1. Avatar Michael says:

    From the very beginning, I knew that we could rebuild any damaged OST files. But what about recovering the vital data? This blog cleared up my total concept. Besides, thanks for the suggested software.

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