You can use the OST to PST Converter Software by SysInfo Tools.
This smart tool Converts emails, contacts, journals, tasks, and to-dos from Exchange OST to PST. AlsoExports password encrypted Outlook OST file to PST format. This tool also Saves Exchange OST file to Outlook PST, MSG, DBX, EML, MBOX & Archive. Provides Support to damaged or corrupted Exchange OST files. Offers Date Range Filter, Search, and Preview options for precise migration. Compatible with the latest version of Windows 10 and MS Outlook 2016. The free OST to PST conversion tool allows you to take a preview of converted files.