How to Convert Orphaned OST file in PST with Stellar Converter for OST?

OST is an Outlook data file that stores a local synchronized copy of mailbox items. The file is encrypted by default with MAPIEntryID GUID and thus, requires authorization from linked MAPI profile to allow access. If the profile is corrupt or deleted from the mailbox server, the OST file becomes inaccessible. Further, the OST file may turn inaccessible due to system crash, abrupt system shutdown, malware or virus intrusion, large size, etc. 

In such cases, you need an OST to PST converter software, such as Stellar Converter for OST to convert inaccessible OST files to PST format.  

About Stellar Converter for OST

Recommended by MVPs and IT administrators worldwide, Stellar Converter for OST is an easy-to-use DIY software to convert Outlook OST files, created by any Outlook version, to PST format with 100% integrity. 

Stellar Converter for OST is a powerful OST to PST converter software to convert inaccessible or orphaned OST files to PST. The software is specifically designed to help Outlook users, Exchange administrators, and IT administrators to recover, backup, and migrate user mailboxes from OST files to PST, existing Outlook profile, live Exchange server, or Office 365 account. It can also convert the mailbox items from OST files to EML, PDF, MSG, RTF, MBOX, HTML, and DBX formats.

Further, you can use the software to troubleshoot and resolve common Outlook and OST file-related errors, such as send/receive error, by extracting the mailbox items from the OST file and saving them in Outlook PST file. 

It requires no technical expertise or knowledge. It can convert encrypted OST files and comes in handy when Outlook is inaccessible, there is no backup, and users cannot access or export their mailbox data to PST via Outlook Import Export wizard.

Stellar Converter for OST can also recover lost or accidentally deleted mail items. Exchange and IT administrators can also use the software to restore deleted mailboxes items on the Exchange server. It provides a batch conversion option to convert multiple OST files to corresponding PSTs simultaneously, saving time and effort. 

Moreover, it does not require any permissions or additional software to work. All you need is the admin credentials of destination mailbox or user account to import OST files into a live Exchange server or Office 365 account. 

Key Features and Pricing

Stellar Converter for OST is available in two editions – Corporate and Technician. The Corporate edition is developed for a single user while the Technician edition is designed for advanced users and administrators. 

Stellar Converter for OST – Corporate Edition

The Corporate edition converts OST to PST, EML, PDF, RTF, MSG, and HTML. Following are the key features offered by the Corporate edition:

  • Converts OST to PST without file size limit
  • Exports mailbox items from orphaned or inaccessible OST files to PST
  • Supports encrypted OST files
  • Displays a detailed preview of OST mailbox items before saving
  • Provides multiple saving options, such as PDF, EML, MSG, RTF, and HTML
  • Advanced Search and Filter options for specific mail item recovery
  • Supports Outlook 2007, 2010, 2013, 2016, and 2019
  • Saves OST scan information in .DAT format to resume conversion process later without rescanning the OST file

Stellar Converter for OST – Technician Edition

The Technician Edition is an advanced version of Stellar Converter for OST. In addition to the features available in the ‘Corporate‘ edition, it also offers the following key features:

  • Batch Conversion option to convert multiple OST files to PSTs 
  • Exports OST file to an existing Outlook profile
  • Export mailbox items from OST file directly to live Exchange server and Office 365 account
  • Exports Contacts (GAL) to CSV format
  • Additional DBX and MBOX file format saving options
  • Compacts large OST files
  • Option to split large OST file into multiple PSTs based on date range or size 
  • Splits and saves large OST mailbox into multiple PST files to avoid corruption

You can download both editions for free. The free demo version allows you to scan and preview unlimited OST files. 

After evaluation, you can choose any edition based on your requirements. The Corporate and Technician editions are available for $79 and $149, respectively. 

NOTE: In addition to the features available in Corporate and Technician edition, the toolkit edition offers 7 additional tools to help you repair corrupt Outlook data files, split/merge/compact PST files, remove duplicate mail items, recover lost or forgotten Outlook PST passwords, and recover deleted attachments and mail items from password-protected OST and PST files.  

System Requirements

Stellar Converter for OST is a highly optimized software. You can install the software on any machine that meets the following minimum system requirements:

  • Operating System: Windows 10, 8.1, 8, and 7 (64-bit or 32-bit)
  • Processor: Pentium class
  • RAM: 2 GB RAM (minimum)/4 GB (recommended)
  • Storage: 250 MB
  • MS Outlook: 2019, 2016, 2013, 2010, and 2007

The software supports 5 languages – English, German, French, Italian, and Spanish, which you can choose during or post-installation.

To learn more about the software performance, read this: Stellar Converter for OST Benchmark Study.


Installation is straightforward, like any other Windows software. 

All you need to do is,

  1. Download the software.
  2. Double click on .exe installable file.
  3. Accept the license agreement and click on Install.
  4. Follow the installation wizard to complete the installation.

After the installation, you can launch the software and choose OST file for conversion. Refer to following screenshots to know more about the software

Figure 1: Select or find the OST file for conversion

Figure 2: Click ‘Convert’ to start OST Conversion

Figure 3: Preview window displaying OST mail items

Figure 4: Corporate Edition save options

Watch this video to learn more about Stellar Converter for OST software.


Stellar Converter for OST is indeed a powerful OST to PST converter tool. One can use it to quickly convert single or multiple OST files, including orphaned or  inaccessible OSTs, into Outlook-supported PST files. In addition, you can also export the converted mail items directly to Office 365 or live Exchange server (available in Technician and Toolkit editions).

About Andrew

Hey Folks! Myself Andrew Emerson I'm from Houston. I'm a blogger and writer who writes about Technology, Arts & Design, Gadgets, Movies, and Gaming etc. Hope you join me in this journey and make it a lot of fun.

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