You can try CubexSoft OST to PST Converter Tool to direct export unlimited OST file to PST format. It allows you to convert all OST emails, contacts, calendars, and other items in Outlook PST file format. All professional and non-professional users can use this Program and successfully convert OST file to multiple file formats such as PDF, MBOX, EML, MSG, DOC, RTF, TXT, etc. To know how to use it before getting its licensed edition, you can first use its Free Demo Edition, which is applicable to import first 25 items from OST file in PST without cost. To open bulk OST files in PST at once, you need to purchase its licensed edition.
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