Try OST to PST Converter wizard. It easily convert offline OST file to PST format with all mailbox data including emails, contacts and attachments. The tool protects entire data integrity and original folder hierarchy during the whole conversion process. Moreover, it helps to recover corrupted or orphaned OST database and helps to convert any size of OST file without restrictions. It is capable to convert all type of OST file including Outlook 365, Outlook.com, Exchange Server, etc. It is workable with or without installation of Microsoft Outlook. 

Try free trial version- https://www.ost2pstwizard.com/