Outlook is an amazing email client and its features are great. But what happens when an issue occurs and you need to recover from your local copy? Outlook works with OST and PST files. The difference between them is that a PST file a mobile file which can be move to any device which has Outlook installed and it can be opened on any computer while an OST file cannot be transferred and it is only used with the account configured. This means that if something happens to your Outlook and you need to recover an item from your OST file, there is no way. Using Outlook an OST is a synchronization between Exchange/ Office 365 or any IMAP provider and if the connection or OST got corrupted before the local copy has synchronized, all the changes will be lost.

Let’s get an example of when we would need to recover from an OST file. A user has been on the move and while travelling without a connection to his Exchange Server he has saved a number of emails, calendar entries and contacts. Since there was no connection to the server, all his saved items in the OST file reside only on the device. Something happens to the server and his profile gets corrupted and cannot open Outlook. The only solution at this stage would be to delete the mail profile and re-configure it. This is the easiest solution as another copy will be synchronized locally on his computer, but the items he created locally will be lost.

Another reason why you would need to retrieve information from an OST file is if there was a user and his mailbox gets deleted since he left the company, his computer remained available and after some time you would need to recover some data from the mailbox. Since it doesn’t exist anymore, the only copy of the email is in the OST file. An OST file is a proprietary file format of Microsoft and there is no way you can just attach it and extract data. Well, not without a third party OST to PST Converter Software like Stellar Converter for OST.

Another use is that since the newer version of Outlook use OST and not PST for IMAP accounts, if the mailbox is deleted or corrupted at the provider, your mailbox cannot be retrieved and all the emails are lost.

Stellar Converter for OST will let you open an OST file, browse through it and recover any items from it. Export to PST and other formats along with the ability to export directly to an Exchange Server or Office 365 tenant.

Key Features

  • Convert from any OST file to PST including multiple files
  • Search, filtering and usability
  • Export to Office 365 and live Exchange Server
  • Export to different formats
  • Compatibility and ease of use

Convert from any OST file to PST including multiple files

Stellar Converter for OST will let you convert any OST file on your local system or network location with no size restriction. The process is fast and all you need to do is have a computer or a device with the application installed and you can convert the OST to PST with the ease of a few buttons. There is no restriction and the process is straight forward. All you need is to either know the location of the OST file or just point the application to the drive and it will search for any OST files. With the application you can also convert encrypted OST files if you have any OST files created by older version of Outlook. If you have a major outage and you need to recover from multiple files, you can simple open multiple files in the application.

After selecting the OST file to scan, depending on the size of the file and any corruption found, you will be presented with the browser of the file. To prevent scanning the files from scratch when re-opening the application you can save the scan results and load them accordingly.

When opening an OST file apart from the mailbox folders, you will also be presented with all the Exchange/Office 365 folders which you can use to recover any deleted or system files.

Search, filtering and usability

When exporting an OST file to PST or another format you wouldn’t want to export everything and then search into a huge PST file. With Stellar Convertor for OST you can search and filter as much and how you like. When browsing a folder you will be presented with the items listed. Here you can simply type in the search on top and while you are typing it will immediately start searching for any items that match.

Another way to search into your OST file is by using the Find Messages button where you will be presented with the To, From Subject and Dat. Within the results you can then search as from the primary windows.

Within both search and filter you can export to any file format apart from PST File.

When exporting from the main window, you can filter the export by folder, for example you need to export only the Inbox folder. All you need to do is deselect the whole PST file and select the desired folder, click on Save Converted File and select the PST format. By default it will not export Deleted Items but you can tick the ‘Include Deleted Items’ and click save.

Export to Office 365 and live Exchange Server

With Stellar Convertor for OST you can exporting directly to a live Exchange Server or an Office 365 mailbox. This is not with the standard version and to do so you would need a Tech Version purchased for the job. Imagine having multiple old OST files which you would need to have in the live mailboxes, with this application you don’t need to do any extra steps. All you need is to connect it with the Exchange Server and import the OST file directly in the desired mailboxes. The same is with an Office 365 mailbox. This is a feature which will reduce big time any import process by eliminating extra steps.

Export to different formats

With Stellar Converter for OST you can export to PST but you can also export to other versions like MSG, EML, PDF, RTF and HTML and all you need to do is just right click on the items to export and select the format.

Compatibility and ease of use

Stellar Converter for OST is a tool which to be honest can be used by anyone. It’s very easy to use and the UI is very familiar and it’s like looking at Outlook. It can convert any OST file from any Office installation being from Outlook 2000 till 2019.

The UI is very simple, all you need to do is just browse the folders and you will be presented with one screen where you can go through the folders, calendar entries, contacts, tasks, journal while viewing the items and preview them. All of this with a click of a button and a very simple and functional UI


When disaster strikes, Stellar Converter for OST will come to the rescue as a tool for your Exchange admins as well as during the day to day work where a user has a corrupted profile and you need to retrieve those long drafts from the OST file. There is no need to tell the user that you can fix his issue in a second by creating a new profile but any drafts, calendar entries, tasks or contacts will be lost. It’s a very good application which I am sure it will come in handy and save you a lot of hassle.

Richard is an experienced tech journalist and blogger who is passionate about new and emerging technologies. He provides insightful and engaging content for Connection Cafe and is committed to staying up-to-date on the latest trends and developments.