I would recommend you use the best Enstella OST to PST Converter Tool to export OST  to PST Outlook 2010. It has many conversion formats and users directly import OST to Gmail, Office365, YahooMail, and Outlook.com. No MS Outlook installation is required for using the software. Try this software with a free demo version and the software provides facilities for users to restore 25 items from each folder of OST files to PST.

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