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Finally, a one-stop solution for inaccessible OST files – Stellar Converter for OST Review

Microsoft Outlook stores mailbox data in Outlook OST (Offline Folder) or PST (Personal Folder) file based on the email type. When a user configures an IMAP, Exchange, Outlook.com, or Office 365 email account in Outlook, it creates an Offline Storage Table File (OST) for mailbox storage. For POP-based email account, Outlook uses Personal Storage Table (PST) file to store mail items.

Unlike PST, the OST file is encrypted and can’t be accessed or imported into other Outlook accounts. Instead, you need to convert the OST file to PST format or export the mailbox items from an OST Outlook profile to PST format using Outlook Import Export Wizard or an OST to PST converter software, such as Stellar Converter for OST.

The software comes in handy when you can’t access Outlook and OST file becomes inaccessible or orphaned. Stellar Converter for OST helps you restore the mail items from such inaccessible or orphaned Outlook OST files to PST and other multiple portable file formats, such as EML, PDF, RTF, MSG, MBOX, DBX, and HTML.

Stellar Converter for OST – An Overview

Stellar Converter for OST is a powerful software to convert inaccessible, orphaned or encrypted OST files to PST format. Recommended by MVPs and IT administrators worldwide, the software can convert OST files without any file size limit and with complete integrity. Administrators and Outlook users can use the software to backup or migrate mailbox items from inaccessible OST files to PST or an existing Outlook profile, Office 365, or Live Exchange server. It also recovers accidentally deleted mail items from the Outlook OST files during the conversion process.

The software helps users troubleshoot and fix common Outlook OST file-related errors, such as OST is not an Outlook data file, send/receive an error, etc., by extracting the mailbox items from the damaged OST file to Outlook importable PST format.

Key Features

The software automatically detects the OST files from the default location. Thus, you don’t need to locate OST files for conversion. However, you can also choose the OST file manually for OST to PST conversion. Following are some key features of Stellar Converter for OST software (available in Corporate and Technician editions).

Stellar Converter for OST – Corporate Edition

  • Converts large-sized OST files to PST
  • Converts inaccessible, encrypted, or orphaned OST files with complete integrity
  • Displays enhanced preview of mailbox items before saving
  • Multiple saving options, such as PST, PDF, HTML, EML, RTF, and MSG
  • Option to Save and Load Scan to resume OST conversion later
  • Advanced search and filter options
  • Supports Outlook 2007, 2010, 2013, 2016, 2019, and Office 365

Stellar Converter for OST – Technician Edition

The Technician edition offers the following additional features:

  • Converts multiple OST files to PSTs simultaneously
  • Splits large OST mailbox into multiple PST files to avoid corruption
  • Compacts large OST mailbox into compressed PST file and stores attachments in a different folder
  • Directly exports OST to an existing Outlook profile, Office 365, or live Exchange server
  • Provides additional DBX and MBOX formats for saving mail items
  • Exports Contacts to CSV format

Stellar Converter for OST – Corporate and Technician editions are available for free download. With the free demo version, you can scan and preview the OST file mail items and save 20 items per folder. To save more, you need to activate the software using a valid Stellar Converter for OST activation key.


Stellar Converter for OST is a highly optimized software that you can install on any system meeting 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

To learn more about Stellar Converter for OST software performance, read this OST to PST converter software benchmark study.

How to Use Stellar Converter for OST?

To get started, download and install Stellar Converter for OST – Corporate edition on your PC and then follow these steps:

  1. Launch Stellar Converter for OST. The software automatically displays OST file from the default location. You can select the file for conversion or click ‘Choose Location’ tab to select the OST file manually.
  • After selecting the OST file, click ‘Convert.’
  • The software displays an enhanced preview of all mail items from the OST file. You can use the search and filter options to find and preview specific emails. Then select the mail items you want to save to PST format.
  • Click ‘Save Converted File’ and then select ‘PST’ format from the given options. Click ‘Browse’ to choose a save location and then click ‘OK.

This will save the OST mail items to PST format.

To export the OST items directly to an existing Outlook profile, live Exchange server, or Office 365, use Stellar Converter for OST – Technician version.


Stellar Converter for OST is a powerful tool that can help administrators and Outlook users restore their mailbox data in the event of a disaster where the OST file becomes inaccessible or the user fails to access the Outlook profile. In addition, administrators can use the software to restore accidentally deleted mailboxes back on the server. In our tests, Stellar Converter for OST performed consistently well with no missing mail items after conversion. It kept all the folders and structure intact after conversion. Thus, you don’t need to put extra effort into managing your email folders.

It also recovers deleted mailbox items and converts OST files without any file size limit or other limitations. You can use it to restore your emails or read an inaccessible or orphaned OST file without Outlook.

If you are looking for a solution to open, access, convert, or migrate mail items from OST file to PST or other formats, Outlook profile, live Exchange Server, or Office 365, look no further. Download the free version of the software to evaluate and check yourself.

Brain Curry

Brian is the news author at Research Snipers which mainly covers Technology News, Microsoft News, Google News, Facebook, Apple, Huawei, Xiaomi, and other tech news.