MS Outlook 2013, like earlier Outlook versions, uses OST file to save a local replica of Exchange mailbox data. This file comes handy when user wishes to work on his mailbox even if Exchange isn’t available. But, it can’t be opened directly in Outlook if its parent account gets disconnected from Exchange. In such a case the OST file is called an ‘orphan’ file and extracting emails and other data from it can become a real pain.


Although Microsoft came up with the concept of using data files to save mailbox data locally in order to make backing up and archiving more convenient, OST and PST files have in some ways complicated mailbox management; and that holds especially true for OSTs. If you access an Exchange mailbox through Outlook, a local OST file is created to save a replica of mailbox data which the user can access and work with even if the mail server isn’t available. However, the basic nature of OST files makes managing mailbox data quite tricky for users.


The need to Restore mails from OST File

OST files have several shortcomings because of which, users often face the need to extract emails and other data stored within these files and save them in some other format:

 

  • OSTs cannot be transferred between different machines. If users need to access their mailbox data saved within OST files on another machine, it cannot be done directly through a simple copy-paste mechanism.
  • If the account that originally created an OST file gets deleted from the mail server, it cannot be opened directly from within Outlook.
  • In Outlook 2013 and 2016, data locally edited and saved within critical folders like Contacts, Calendars, Sent Items, etc. is not synced with the mail server and is thus not backed up there. In the event of damage to OST file, there’s no direct way to regain access to that local data since it doesn’t exist on the server.

Users who faced the need to extract OST file data because of any of the above-mentioned reasons make use of manual as well as automated ways to achieve it. For your reference, we’ve compiled a list of the most widely used and accepted techniques you can use to restore OST files if you’re sailing in the same boat.


Manual techniques to Restore OST files


In no specific order, these techniques can help you regain access to all your Exchange or other IMAP account data depending upon your exact problem scenario:


Scenario 1: If your Exchange account is intact but OST file gets corrupted


This is one of the most frequently encountered problems by Exchange users. OST files get damaged easily but if your Exchange profile is intact and you are in the habit of regularly syncing your local data with your server mailbox, regaining access to all your data should simply be a matter of manually creating a new OST file and downloading your mailbox data from the server again. Here are the steps:


  1. Quit all running instances of Outlook and open Control Panel
  2. Open the “Mail” option and in the ‘Mail Setup’ dialog box that opens, click on “Email Accounts”
  3. The next dialog that opens will display all your Outlook profiles / accounts. Here, click on the “Data Files” tab and choose the respective OST file from the list
  4. Now click on “Open File Location” to open the Windows Explorer window with the OST file’s location
  5. Close the ‘Account Settings’ and ‘Mail Setup’ windows
  6. In the Explorer window, create a copy (backup) of the OST file. Thereafter, right-click on it and click on “Delete”
  7. Start the Outlook application again to automatically create a new OST file for that account (doing so will download all the data from the Exchange server into the newly created OST file)

 

You should remember that if you’re using Outlook 2013 / 2016, only the data residing on the mail server will be downloaded into the new OST file. This will include your emails and the folders you have manually synced with the Exchange account. Any local data will not be downloaded since it doesn’t exist on the server. To get access to any such data you will need to convert the old OST to PST format and then open it directly within Outlook. You can either use the Outlook “Import & Export wizard” to convert OST to PST or take the help of reliable software Stellar OST to PST Converter to do so (skip to last section to discover how this product can help).


Scenario 2: If your Exchange account has been deleted or lost


If this happens, your “orphaned” OST file will most likely become useless since you won’t be able to open it directly unless you reconnect to Exchange and re-sync it. For this you will need a unique MAPI address to act as a bridge between Outlook and the Exchange server. However if this isn’t an option, the only way to access the data contained within the orphaned OST file is to convert it to PST format using Stellar OST to PST Converter. (Here you won’t have the option to use Outlook Import Export Wizard since you’ll need to open the OST file from within Outlook and without Exchange that won’t be possible).


Best Automated Solution to restore mails from OST file


If the manual technique doesn’t work or if you are dealing with an orphaned OST file, converting it to PST format is a task best handled by a professional product like Stellar OST to PST Converter. The advanced software is equipped with some very powerful algorithms that allow it to convert even the most severely damaged OST files to PST format files that can be used to access all mailbox contents including emails, attachments, contacts, calendars, notes, journals, etc. This software is your best bet if you wish to perform conversion of encrypted OST files or wish to extract only selected emails from within OST files and save them in MSG, EML, RTF, HTML, or PDF formats.

 


Final Thoughts…


So should a user completely shun the usage of OST files? Well obviously that isn’t an option since OST files are the Microsoft norm for saving Exchange data locally. What is needed is for users to stay aware of the techniques they can use to regain all their mailbox data if any disaster like virus infection or accidental deletion or severe corruption befalls their OST files. Converting OST files to PST format is the best way to salvage all the data stored within them and thus, having a product like Stellar OST to PST Converter handy goes a long way.