OST-to-PST conversion is an added feature of Recovery Toolbox for Outlook (download). Recovery Toolbox for Outlook can convert .ost files from any version of Microsoft Outlook or any version of Microsoft Exchange Server into the .pst file format without Exchange Server or Windows Domain Controller.

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Features of OST-to-PST conversion software:

  • Converts *.ost files of Microsoft Outlook 97/98/2000/XP/2003 (ANSI .ost files)
  • Converts .ost files of MS Outlook 2007/2010/2013/2016 (UNICODE .ost files)
  • Converts password-protected files
  • Converts encrypted .ost files
  • Converts damaged .ost files
  • The ability to split the output pst file into several volumes of a maximum size defined by the user
  • The ability to save items as MSG/VCF/EML/TXT files
  • Converts *.ost files after failure ScanOST recovering
  • Converts *.ost files without connect with Windows Domain Controller
  • OST2PST conversion without Microsoft Exchange Server
  • Converting OST to PST for files of more than 4 GB

Recovery Toolbox for Outlook is OST-to-PST converter and an Outlook OST recovery tool at once.

How to convert ost to pst file

This OST-to-PST converter is an easy-to-use tool that operates like a wizard. With it, you can convert an .ost file to the .pst file format in a few simple steps. No special know-how is needed in order to use the Recovery Toolbox for Outlook OST-to-PST converter.

Microsoft doesn't currently offer a special Outlook OST-to-PST converter. All OST2PST converters have been designed by ISVs. Recovery Toolbox for Outlook, however, has a demo mode that lets you convert five objects per folder.

What versions and types of .ost files can be converted to .pst files?

Recovery Toolbox for Outlook can read *.ost files any versions of Microsoft Exchange Server, any version of Microsoft Outlook (32- or 64-bit, ANSI or UNICODE). Software can read and convert *.ost files with any size of file.

Why size of result pst file smaller than size of source .ost file in several times?

The size of the converted .pst file shows the actual size of information stored in the ost file. If you do not make archives and do not start Cleanup Tool regularly for the original Offline Storage Folders, then the .ost file size is only growing. As a result, only 5-10% of the file can be used for a real user’s data.

What version of pst file will be after OST2PST conversion?

For the use of OST-to-PST conversion on a computer running Microsoft Outlook, the .pst file version will be the same as that installed in Microsoft Outlook. If the computer has Microsoft Outlook 2007 or higher installed, the size of the resulting .pst file can exceed 2Gb. If you use MS Outlook 98-2003, the size of the resulting file will be limited to 2Gb. In this case, Recovery Toolbox for Outlook will create several .pst files in which to store all the data from the source .ost file.

How export data from .ost file to other Email client software

Recovery Toolbox for Outlook exports messages, contacts, appointments and other data from *.ost files as MSG files. The software converts and saves all data from .ost files to the .msg file format. Later, the user can drag and drop or import the saved .msg files in any of the popular client software programs, including Lotus Notes, Microsoft Live, The Bat, Eudora, Incredimail, Mozilla Thunderbird, etc.

How do you import .ost files in Outlook?

Microsoft Outlook has no function with which to import data from .ost files. To open an .ost file in Outlook, the Exchange Server and Windows Domain Controller must be working and available for user authentication in both of the respective services. Only after that is it possible to transfer the contents of an .ost file that is open in Outlook to a .pst file that is also open in Outlook.

If the Exchange Server or Windows Domain Controller isn't accessible or doesn't work, or if the user can't be authenticated, access to the data will be denied and Outlook won't open the .ost file.

How do you import data from an .ost file in Outlook when the Exchange Server or Windows Domain Controller isn't accessible?

The original .ost file must be converted to a pst file using Recovery Toolbox for Outlook and then opened in Outlook. Conversion from OST to PST using Recovery Toolbox for Outlook doesn't require the availability of Exchange Server or Windows Domain Controller.


  1. Windows 98/Me/2000/XP/Vista/7/8/10 or Windows Server 2003/2008/2012 and above.
  2. Microsoft Outlook 98 or higher must be installed on the user’s computer at the time of conversion (excluding Outlook for Office 365, Outlook for iOS and Outlook for MacOS).


  • This product does not export contact groups.

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Additional information, sources and resources for a PST files repairing


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