Read time 8 minutes

Have you ever been in a situation where your OST (Offline Storage Table) file gets inaccessible due to corruption? This problem may become the reason behind several issues in the Outlook application, such as it stops working, abnormal behavior, sudden application crash, mailbox not opening, etc. An OST data file stores a synchronized copy of mailbox items in the local system, you can make changes in the application even in offline mode. Once you go online, the performed changes will get modified in real-time with the Exchange server. But, if the OST file gets damaged due to various events, such as virus or malware intrusion or system crash, it stops synchronization and error messages in the application.

You do not need to worry, as there is a solution to this problem: recreating the OST files. Nowadays, numerous ways to rebuild or recreate OST files in Outlook make the specific process reliable.

Reasons behind damaged and inaccessible OST files

OST files can encounter corruption issues, such as becoming damaged or inaccessible, leading to data loss. Here are eight reasons why your OST files may become inaccessible or damaged:

  1. Sudden power outage or system crash when Outlook is running.
  2. Malware or virus attacks can also lead to the corruption of OST files.
  3. Accidentally deleting mailbox data or corrupt system files.
  4. Exceeding the storage limits and oversized OST file size leads to such issues.
  5. Improper synchronization with the exchange server while switching network modes can lead to inaccessibility of OST files.
  6. Human error, such as mistakenly disconnecting the network connection.
  7. Bad sectors on the hard drive can damage the OST files.
  8. Use of unreliable third-party software or improper installation and configuration of the Outlook profile.
File repair options in different versions of Outlook

Before you recreate OST file, file repair implementation can also be possible to repair the corrupted files in Outlook. In the 2010 and 2013 versions, the repair option focused on the design for Outlook installation files and registry entries. However, in versions like Outlook 2016 and 2019, there are easier ways to repair and create OST file again.

Try expert recommended free methods to convert OST to PST file

  • Step 1: Export the mailbox as a PST file
  • Step 2: Use ‘Archiving’ to save OST emails to PST
Recreate OST files in Outlook 2013, 2016

Recreating the file is a straightforward way to deal with all forms of OST file issues. When you delete or rename your OST file, Outlook will automatically recreate OST file. Experts in the field mention taking a backup of the OST file before proceeding. Based on the following Outlook version, you can follow the below steps to create OST file in Outlook.

  1. Delete the Outlook OST files

    OST file is an offline version of the Exchange user mailbox. If it gets deleted, a fresh copy can be retrieved from the Exchange server. To recreate OST files, you need to follow the steps shared below:

    1. First, close the Outlook application.
    2. Next, open Mail from the Control Panel.
      Recreated the OST file in Outlook 2016
    3. It will open a dialogue box named Mail Setup – Outlook. You need to click on Email Accounts.Recreated the OST file in Outlook 2016
    4. The newly opened dialogue box Account Settings will have all the Outlook accounts. Click on Data Files, choose the OST file, and then click Open File Location (to go to the location where a particular OST file is residing).Open File Location
    5. Right-click on the OST file and click the Delete option to delete the file.Delete OST File
      Note: Before deleting the file, close the Account Settings and Mail Setup windows; otherwise, the system will give an error message.
    6. Start the Outlook application again. It will automatically create a new OST file for the account (downloading all the data from the Exchange server).
  2. Change the extension of the file
    By editing the file extension of an OST file, you can safely recreate an OST file. Here is how:
    • Close the Outlook window. Enable the ‘File Name Extensions‘ option from the View menu in File Explorer.Enable File Name Extensions
    • To rename the OST file, right-click on it and tap on Rename.
    • Rename the OST files and remember that the file name must end with .bak.
    • Launch Outlook now. Microsoft Outlook rebuilds the OST file and starts synchronizing messages from the server’s mailbox.
Repair the OST file

The above method to recreate OST file will work only when the Outlook account and Exchange server are in-sync. If the Exchange server is down or there are network issues, the method may lead to permanent data loss. You should have the original Outlook profile and Exchange Server availability for the above methods to work. But if you use a professional OST recovery tool, you can recover OST files in any situation. So, it is highly recommended that a competent third-party recovery tool must be used to handle the corrupt OST files. Kernel for OST to PST Converter is one of the most trusted and widely used data recovery tools that can retrieve data from any corrupted OST file and save it to a PST file.

Below is the process of restoring and converting an OST file to a PST file using the tool. This process works with the OST files of all the versions of Exchange/Outlook.

  1. After you have installed the software, start it; the ‘Source File Selection’ window will open instantly. Here, you need to click the Browse button to add the OST file.add the OST file
  2. After selecting the OST file, click the Next button.Next to select OST file
  3. The Information window will tell you about the recovery process and various output formats available for saving the recovered data. Click Finish.Finish recovery process
  4. The tool scans the OST file and restores the data. Let the process finish.scans the OST file
  5. The OST to PST Converter tool has recovered all the data, and you can check all the folders in the exact hierarchy as they were in your Outlook mailbox. Check the items and see their preview also. Later, click the Save the data
  6. Choose PST File (MS Outlook) as the output format.choose PST file format
  7. Choose diverse options for saving the file. Also, you can split the PST file after reaching a definite size and attach a prefix to the store name. Then click the Next button.choose various option to save
  8. Click the Browse button to select the location for saving the PST the location
  9. After saving the PST file, the tool will give you a message with the location of the PST file.find message with the location of the PST file

Final say

MS Outlook saves the OST file in the user’s computer, and the data file is susceptible to threats like software corruption, hardware malfunction, accidental deletion, etc. If you follow the valuable methods presented in this article, then you may recreate OST file and re-access your account effortlessly. The best-suited solution will be using Kernel for OST to PST Converter, as it will recover the severely corrupt and deleted items from all the folders. After recovering all the folders in their correct hierarchical order, you can convert data into available formats. Also, this OST to PST Converter works with all Exchange/Outlook versions.

Q- Why does Outlook keep creating corrupt OST files?

A- Outlook users may sometimes experience corrupt OST files, where the reasons can vary by a range of factors. 
One cause is a malware or virus infection that can cause file corruption. 
Another is an improper shutdown of the computer while the OST file is open. 
Also, hardware issues such as bad in the hard drive can also lead to file corruption. 
Compatibility issues between the OST file & the Outlook version may be a factor. 

Q- Does recreating the Outlook profile create a new OST file?

A- Outlook will automatically create OST file when a new profile is generated, streamlining the process for users. This eliminates the need for a manual backup, saving time & ensuring that the new profile is up & running as quickly as possible. This feature sets Outlook apart from other email clients & provides a seamless user experience with productivity.

Q- Can we recover damaged OST emails easily?

A- The ScanOST for Outlook is a tool that can help retrieve and export the emails you thought were lost forever. This program is specifically designed to navigate Outlook’s system files and locate emails deleted from the Deleted Items folder.

Kernel for OST to PST