How to Fix Corrupt Outlook OST File?

What is an OST File?

Offline Storage Table simply called as OST file, is a Microsoft Outlook storage file. The benefit of OST file is that it allows users to work on Outlook even if the application is disconnected from Exchange Server

So, you can compose new emails, save them in drafts, read or delete existing emails, etc. even in offline mode. Once the internet connection is retrieved, whatever changes you have made to the Outlook OST file gets automatically synchronized with Exchange Server.

Actually, OST files are a carbon copy of mailbox lying on Microsoft Exchange Server and are stored on computer hard drive. Therefore, damage to Exchange Server does not affect OST file saved on your hard drive.

How OST File Gets Corrupt or Damaged?

We know that Exchange Server issues do not affect OST file saved on the local drive. But, there are few factors which affect OST file, like corrupted storage medium where OST file is saved, synchronization failure with Exchange Server, etc. hence your OST file gets corrupted or damaged.

Solutions to Fix Damaged/Corrupted OST File:

Method #1: OST Integrity Check Tool

The OST Integrity Check is a Microsoft inbuilt repair application used to diagnose and repair OST file. The tool works by scanning both your OST and mailbox file running on Exchange Server. It compares items and folders in each file and attempts to resolve synchronization differences between them. To use this tool, you must be connected to your Exchange account server.

How to Fix OST File Using Scanost.exe?

Step 1: Terminate MS Outlook before starting the repair process.

Step 2: Open Scanost.exe by double-clicking on it, the default location is drive:\Program Files\Microsoft Office\OFFICE12 (the destination folder path varies depending on your Outlook version).

Step 3: If you have multiple Outlook accounts, the tool will prompt you to choose the OST file that you need to repair.

Step 4: If you are asked to Work Offline, click Connect and choose the option according to your need.

Step 5: Select Repair Errors checkbox to automatically resolve errors while scanning OST file. At last, click on the Begin Scan button.

Limitations of Scanost.exe:

There are few drawbacks, which are related to OST Integrity Check Tool like:

  • Capable of repairing only minor corruption issues
  • Do not recover data from OST file
  • There’s no guarantee for the safety of the data
  • The tool is unavailable in Outlook 2010 or later release

Method #2: Automated Way to Fix Corrupt/Damaged OST File

Nevertheless, you cannot fully rely on this inbuilt tool to repair corrupt OST, as it has limitations. So, in such cases, you need a professional tool. One such tool is Yodot Outlook PST Repair. This tool is amongst the best repair utilities ever to fix your OST file corruption due to any reason. The best thing about using this software is that after repairing OST file, it recovers Outlook emails, Attachments, Notes, Journals, meeting requests, and other attributes that are disappeared from Outlook PST. The tool scans corrupted OST, copy its contents to a new file and fix issues; thus keeping your original file intact.

Along with OST, the tool supports corrupted PST file repair. And while moving your PST to another physical location through USB drive, things can go wrong making your pen drive corrupt. In such instances instead of thinking my pen drive is corrupted and unreadable, you can make use of Yodot data recovery products to reach your PST and other files on USB flash drive with utmost ease.

Steps to Repair Corrupt OST File

Step 1: Close Outlook and run Yodot Outlook PST Repair software on your computer. Next, click on

  • Open PST File to browse for corrupt OST file which is to be repaired
  • Find PST File to search and select the OST file
  • Select Outlook Profile to choose a particular Outlook profile if you have multiple Outlook accounts

Main Screen

Step 2: Select Normal Scan if your OST file has minor corruption or Smart Scan if your OST file is severely corrupted. Mention location to save repaired OST file and click on Repair button.

Click on Repair Button

Step 3: The application initiates the repairing process, after which it shows all the recoverable items in Outlook styled interface. Check and save your healthy OST file.


Things to Be Noted:

  • Never exit your Microsoft Outlook application improperly
  • Maintain a regular backup of your OST file

What is ScanPST? Where ScanPST is located and how to fix Outlook using ScanPST...

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