• Recover and open OST file items for free using EdbMails.
  • Recover and convert OST file to PST from corrupted, password-protected, encrypted, damaged and orphaned files.
  • Preview and convert individual mail items such as Journals, Tasks, Mails, Contacts and Calendars.
  • Recover and convert accidentally deleted Exchange server mailboxes.
  • Convert large OST files without any restrictions.
  • Directly migrate the contents of an OST file to Office 365 and Exchange.
  • Convert OST to multiple formats such as EML, HTML, MHT and PST.

(4.9/5 Rated)

  • Lifetime license
  • 30 days- Money back gurantee
  • 24/7 Live chat support

Why do we need to convert an Outlook OST to PST file?

You may decide to convert an OST file to Outlook PST mainly because your OST file has been corrupted, orphaned, or damaged. You may want to restore your Exchange mailbox from your OST file or you have forgotten your passphrase / encryption and wanted to recover your mailboxes from the OST file. In addition, you may want to archive your OST files in Outlook PST format as Outlook is one of the widely used file formats to store your mailbox data.

How to convert an OST file to PST?

EdbMails software allows you to recover OST and convert it to PST in 3 easy steps.

Step 1: Install the application

Download and install application on your computer. Login to the EdbMails application.

Step 2: Select the OST file

Browse and select the OST file that you wish to convert to PST. Upon selecting the OST file, EdbMails will perform the automatic recovery of your OST file and display all contents of the selected OST file.

Step 3: Convert to PST

Select the folders such as Inbox, Outbox, Contacts, Calendars etc., and click the 'Export to PST'. Upon export, the data will be stored in Outlook PST file formats. Open the PST file using Outlook to view the recovered / exported data.

Benefits of using EdbMails OST conversion tool

Benefits of using EdbMails OST conversion tool
  • Recover OST file without any dependency on Exchange server services.
  • Convert offline OST file into Outlook PST without internet connection.
  • Offline OST conversion to PST without Active Directory or Windows Domain Controller Credentials.
  • EdbMails is the best recovery and conversion tool with 100% accuracy and security.
  • The tool supports Outlook versions 2019, 2016, 2013, 2010 etc.
  • It retains the exact folder structure on the source and target without any data loss.
  • The software generates detailed log reports for complete verification of the exported or migrated items.
  • EdbMails is a cost-effective tool for small, medium, large organizations as well as for personal use.
  • You can contact EdbMails 24/7 customer support for any assistance even when using the trial version.
  • You get free software updates and upgrades with lifetime licenses.

Salient Features of EdbMails tool

Preview OST file data prior to extraction for free of cost

EdbMails Free application allows you to view the OST file data before exporting it to Outlook PST. It is designed to organize and display the content of your OST file so that you can simply verify and export only what you need or everything from your OST file to PST.

Extract PST from corrupt and damaged OST files

EdbMails application helps you to automatically recover and export corrupted and damaged OST files to PST format. In other words, you can directly extract PST files from your OST file. It supports the extraction of all emails, messages, contacts, calendars, etc., in your OST files to PST. In addition, you can also export your OST file to a few other file formats such as EML, MHT and HTML etc.

Recover an orphaned OST file and export its data

The OST file is orphaned and you want to recover its data without hassle then EdbMails OST to PST converter is the best bet for your requirement. EdbMails will always ensure the successful recovery of your inaccessible and orphaned OST files.

Recover deleted Mailbox items, folders from OST file

EdbMails is the best tool to recover accidentally deleted mailbox folders, emails and messages from an OST file. It supports recovery of both soft-deleted and hard-deleted user mailboxes.

Recover and convert encrypted OST files

Errors in the encrypted OST files may result in mailbox data inaccessibility. You can fix this by using EdbMails to export and convert such encrypted files to PST files. It is not necessary to use a key to export the encrypted OST files. After the conversion, you can successfully access your mailbox data from the exported PST file.

Recover Metadata and Attachments

You can recover emails with the metadata like ‘Message headers’, ‘Message-ID’, ‘Subject’, ‘To address’, ‘From address’, ‘Date and Time’, ‘Cc’, Bcc’, etc from OST Outlook data files. You can also save background images, attachments (with all extensions), appointments, meeting schedules and so on using this tool.

Recover and export unlimited OST files

EdbMails allows you to recover an unlimited number of OST files and convert each recovered file into a separate PST file. Furthermore, there are no restrictions on the size of the source file for the recovery and export operations. It recovers and exports the entire OST file data in a few clicks.

Granular recovery and conversion of OST file

Using EdbMails software you can perform granular restore / export of individual mail items from the OST file. In general, granular recovery reduces the recovery time by allowing you to perform conditional (individual or group of items / messages) export operations.

Recreate and convert OST file from Outlook 2019/2016/2013/2010

EdbMails can recover inaccessible and corrupt OST files from Outlook versions 2019, 2016, 2013, 2010, and 2007. This allows you to access the file data and mailboxes without having to worry about the different Outlook versions.

Migrate OST to Live Exchange

EdbMails can help you in reinstating your Exchange server mailboxes. It can directly migrate mailbox data such as emails, calendars, contacts, tasks etc., from an OST to any Exchange server. It supports granular incremental migration for Exchange migration to avoid duplicate items migration.

Convert OST to PST from all the Exchange and Outlook version

Whatever version of Exchange server or Outlook you're using, EdbMails can convert OST files from all versions such as 2003, 2007, 2010, 2013, 2016 and even the latest 2019.

Convert different mail items such as email, contacts, tasks etc

EdbMails can export mailbox data from the source OST file by keeping the folder structure intact. This will help you to export the entire mailbox contents including emails, contacts, calendars, tasks, journals etc., with a single click.

Convert only specific emails, folder and its items from OST file

EdbMails software allows you to select the required emails and folders in the OST file and then export it to PST. Selectively export required items like Inbox, Contacts, Calendars folders and the items in the corresponding folders by switching to filter settings where you can set include / exclude filters based on Date, Subject, To, Cc, Bcc, Attachment Name etc.

Split a large OST file to multiple PST files

Converting a large OST file to PST directly increases the likelihood of PST file corruption. Switch to EdbMails and utilize the PST split option to convert a single Outlook data file (OST) to multiple PST’s.

Supports Unicode and ANSI OST file formats

The tool supports the export operation of OST files which are created in different languages (Unicode or ANSI), non-English (Unicode) characters and special characters.

Detailed log report for OST file conversion

EdbMails automatically generates log reports which will help you to know the status of the complete conversion operation. The report consists of the total number of exported or migrated items from each and every folder and it indicates the success or failure of the process.

Restore and convert Exchange Mailbox using OST file backup

When recovering Exchange mailboxes, old or cached OST files pose a problem. EdbMails can easily recover Exchange mailboxes from such cached or backup files and convert them to PST.

Import OST file contents to Office 365

EdbMails is a fast, secure and easy to use migration tool for migrating your OST files directly to Office 365. It can seamlessly migrate mailbox data such as emails, calendars, contacts, tasks etc; The tool uses advanced incremental migration technique for Office 365 migration to avoid duplicate items migration.

System requirements, supported versions and scenarios

Processor icon


Quad-core CPU with 1GHz processor. Supports both 32-bit and 64-bit systems

OS icon

Operating System

Windows 7, 8, 10, 11

RAM icon


512 minimum requirements.
(4GB recommended)

Hard Disk icon

Hard Disk Space

20MB free space for installation

Outlook icon

Outlook versions

Outlook 2003 to 2019 supported

Comparison of OST to PST Converter Trial and Full Version


Free Trial Version

Full Version

Recover corrupted, password protected, encrypted, orphaned, damaged and ransomware victim OST files  
View the contents of the file  
Export individual mail items to EML, MHT and HTML  
Convert the entire OST file to PST30 items per folder 
Technical support 24/7  
Apply filters to export selected mail items  
Migrate contents of OST to Office 365, live Exchange (Corporate and Technical Editions)30 items per folder 


  1. How to convert corrupted OST files with the EdbMails free tool?

    Follow the steps below to recover and convert corrupted OST files

    1. 1. Download and install EdbMails free OST to PST tool from the link.
    2. 2. Browse for the Offline Outlook OST file on your PC.
    3. 3. The tool will recover the corrupted OST and display the contents in the form of a tree view.
    4. 4. You can select individual mails and export them to MHT, HTML or EML or convert them to PST.
  2. Is there a tool for viewing and converting OST files for free?

    Yes. EdbMails free tool will allow you to recover, preview, open and convert the contents of an OST file.

  3. What is the best OST to PST converter?

    EdbMails is the best OST to PST converter software. It has an easy-to-use interface and can easily recover all corrupted or problematic files. You do not need any additional applications or dependency on Exchange server services to view the contents of the OST file. The offline recovery and export means that you do not even have to be connected to the internet to perform the conversion.

  4. What can I use the EdbMails free tool for?

    You can use EdbMails free trial version recover and preview all the contents of an OST file. With the free version, you can additionally convert 30 items from each folder of an OST file to PST or directly migrate 30 items from each folder of an OST file to Office 365/live Exchange server.

  5. How to convert an OST file to PST or save an individual email message in different file formats?

    Open EdbMails and select the OST file which you need to convert. You can save individual mail items as EML, MHT and HTML or directly convert it to PST.

  6. Can I open an OST File without an Exchange server or Outlook profile?

    Yes. EdbMails' free tool is the best solution to open an OST file without depending on an Exchange server or any active Outlook profiles. This means that you can simply open an offline OST file in EdbMails to recover and view all the contents of it. You do not need to be connected to an Exchange server or require any Active Directory services.

  7. How to convert OST to PST with EdbMails?
    1. 1. Download and install the EdbMails software.
    2. 2. Browse for the location of your OST file and select the items you wish to export.
    3. 3. Click Convert to Outlook PST to convert the contents to Outlook PST.
  8. How to open an old OST file that I have on my PC?

    Use EdbMails application for recovering any OST file. After recovering the contents you can preview and convert the items of your choice to multiple formats such as PST, MHT, HTML, EML.

  9. Do I need to install Microsoft Outlook on my PC for the OST conversion operation?

    It is recommended to install the latest version of Microsoft Outlook if you are converting the OST file to PST file format. However, Outlook is not required if you are migrating the contents of an OST file directly to Office 365 or live Exchange server.

  10. Does EdbMails support IMAP OST files and can it recover files that have failed through ScanOST?

    Yes, the application supports recovery and conversion of OST files from Exchange server, Microsoft Outlook and IMAP. It also recovers all such files that you were not able to recover through the ScanOST tool.

  11. How does EdbMails ensure a successful file conversion?

    The tool maintains an exact copy of the source mailbox in the target PST file. For example, after performing the OST to PST conversion, all of the mail data in the target PST is an exact replica of the data in the source file, with no changes. The application ensures that no data is lost or corrupted during the process in this manner.

  12. Can I perform OST to PST conversion without losing data from EdbMails?

    Yes, you can safely use EdbMails without losing any data. It is an ISO 27001:2013 certified tool that preserves the source folder structure on the target. There is no data loss with the tool and the meta-data used for performing the export operation is stored on your local environment with AES-256 military grade encryption.

  13. When and why do I need to convert an OST file into a PST file?

    An Outlook OST file is an offline storage file from an Exchange server or Outlook. You need to perform the conversion in the following cases.

    1. 1. You cannot access your OST file either because it is corrupted, damaged or encrypted.
    2. 2. You need to recover the contents such as mails, contacts, tasks.
    3. 3. Your Exchange server might crash leaving you with an orphaned OST file.
    4. 4. You need to rebuild the OST file in case of Exchange server disasters.
    5. 5. You wish to take a backup of the OST file and convert it to PST.
    6. 6. You need to move the mail contents and data to another mailbox.
    7. 7. You face difficulties in viewing or exporting the OST file from Microsoft Outlook.
    8. 8. The OST file has grown very large and Outlook crashes when you try to open it.
  14. What is the difference between OST and PST?

    To put it simply, an OST file is a Microsoft Outlook or Exchange server offline storage file. This file cannot be simply copied and transferred to another computer. When you don't have access to the internet, an Exchange server or Outlook accesses the OST file to display the mailbox contents. A PST file, on the other hand, is a file format stored by Microsoft Outlook that is portable, making PST an excellent backup option.

  15. Can I save or migrate OST items to Office 365?

    Yes. Using EdbMails software, you can directly migrate the contents of an OST file to Office 365. The migration is incremental and direct which means that there are no intermediate steps or conversions during the migration. The tool ensures that no duplicate entries are migrated to the target on successive migration operations from the same computer.

  16. Can I open an OST File without an Exchange server or Outlook profile?

    Yes. EdbMails free OST to PST converter tool is the best solution to open an OST file without depending on an Exchange server or any active Outlook profiles. This means that you can simply open an offline OST file using the EdbMails application to recover and view and export all the contents of it. You do not need to be connected to an Exchange server or require any Active Directory services.

  17. Can EdbMails convert large size OST files to PST or recover special characters from mailboxes?

    Yes, The tool can handle large size files as well (greater than 1TB) and can easily recover and convert non-English Unicode special characters such as Scandinavian, French, German and many other languages.

  18. Can I export the contents of the OST based on a specific Date or Sender?

    Yes, With EdbMails, you can filter the mail items based on specific Date, Senders or even the Mail subject. There are many filter options using which you can selectively export the contents instead of converting the entire file.

  19. What items are exported with EdbMails OST to PST converter software?

    You can export mail items, calendars, contacts, Alias Distribution Groups, Tasks, Notes, Journals, Public Folders, Archive, and Shared Mailboxes, Meeting invites, and so on.