Best Way to Convert Orphaned OST file to PST

Orphaned OST files are the ones that are not linked to their parent Mailbox. OST files can get orphaned for a number of reasons, but the most common is when users have changed their login credentials in Outlook and never updated their OST file. 

This leaves you with an unlinked OST file that cannot be accessed unless you reset your password and link it to your new Mailbox again. As you are reading this article and probably you don’t want to do that — and we don’t blame you! 

Luckily, there are other ways to rescue your orphaned OST file from Outlook without having to reset your password and start over from scratch. In this article, we will look at different third-party tools and methods through which you can convert orphaned OST files to PST files so they become accessible once again.

Additional Tips: The user can click on to Open OST file in Outlook 2019 and below versions. 

Know Why Your OST file became orphaned

The Exchange offline folder (OST) file is a nearby and offline duplicate of the Exchange server’s mailbox. When the mailbox on the server is no longer accessible for any reason, the OST file is referred to as orphaned. 

There are numerous reasons why your Exchange offline folder (OST) file may become orphaned. We divide them into two categories: hardware reasons and software reasons. Before proceeding, consider the following Exchange OST file orphaned reasons:

Due to Hardware

When your hardware is damaged while storing or moving the data of your Exchange Server databases (EDB), a data catastrophe occurs, and the server crashes. OST files will be orphaned around that time. There are basically three types:

  • Failure of a Data Storage Device:

For instance, suppose your hard disc contains some bad sectors, and your Exchange Server databases are stored on these sectors. Then you might only be able to read a portion of the database file or the data you read is incorrect and riddled with errors. A data corruption of this magnitude will render the database inaccessible and your OST file orphaned.

  • Power Outage or Unusual Server Shutdown:

Improperly shut down the Exchange server while it is accessing the databases, your databases may be damaged and your OST file orphaned.

  • Failure or malfunction of the controller card

If a caching controller is used with Exchange Server, any malfunction or failure will result in the loss of all cached data and database corruption, rendering the OST file orphaned.

Due to Software

Furthermore, Exchange OST files can become orphaned as a result of software issues.

  • Erase, disable, or deny access to the Exchange Server Mailbox.

If your server administrator erases or disables the Exchange Server’s mailbox compared to the OST file, or if your access to the mailbox is denied. Your OST file is now orphaned.

  • Viruses and other harmful software

Many viruses will contaminate and harm Exchange Server databases, rendering them unusable, leaving the OST file orphaned. You are strongly advised to install quality anti-virus software for your Exchange Server framework.

  • Errors caused by humans

Accidentally erasing databases, mis-parceling the storage device, and mixing up the working framework will all render the Exchange Server database inaccessible, rendering the OST file orphaned.

Convert Orphaned OST file to PST file for OST

A sophisticated program called Stellar Converter for OST can transform inaccessible OST files into Outlook PST files.It converts every element of the mailbox, including emails, attachments, contacts, calendars, etc., with 100% accuracy and without regard to file size.

Features for OST are:

  • PST conversion for encrypted, orphaned, or IMAP OST files
  • Supports the versions of Outlook 2021, 2019, 2016, and older
  • Data from OST files are exported to Office 365, Outlook, and live Exchange.

Steps to Use Converter for OST:

Step 1: Launch The Converter for OST in the first step. Select Outlook OST in the top ribbon’s Home tab. A pop-up window will appear with the options to List Profiles or Choose Manually.

Step 2: The List Profile option displays all of the OST files stored in the Profile List tab’s default location. You can convert the OST file by selecting it from the list and clicking Convert. You can also browse manually by clicking Choose Manually.

Step 3: Once the conversion is complete, the software displays a preview of the Outlook mailbox folders and deleted items (in red) in the Left pane. You can preview mail items by clicking on them, and you can save mail items by selecting them.

Step 4: Search for emails using various search parameters such as ‘To,’ ‘From,’ ‘Subject,’ ‘Date,’ and so on, and save them individually or in a group.

Step 5: On the Home tab, click Save Converted File. A window will appear with file formats for saving the extracted mailbox data. Click Next after selecting PST.

Step 6: Click Browse to select a save location, and then check or uncheck the Restore Deleted Items and Auto split PST file options as needed. You can also apply filters by clicking the Apply Advanced Filter link and then clicking OK.

Step 7: Clicking Apply Advanced Filter brings up a new dialogue box where you can include or exclude mail items based on email ID and date range.


The best way to tackle an orphaned OST file issue is to find a solution that allows you to open and access the contents of that file. All of the methods we have explored in this article will allow you to do that. You can choose whichever option you like best and convert orphaned OST file to PST format so that you can access your emails again. 

When it comes to accurately and easily convert your OST file, use great tool like for OST to PST Converter will save you a lot of time.

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Lee Clarke
Lee Clarke
Business And Features Writer


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