Here is the most advanced solution to convert OST to PST file with the use of KDETools OST to PST Converter Software is the perfect way to recover OST file and convert it into Outlook PST file. It has the ability to import a large file size of OST by splitting it into many PST files without installing MS Outlook. You can smartly recover all OST file properties like To, Bcc, Cc, Date, Time, Subject, Images, and all Attachments and convert it into PST, Zimbra, Gmail, EML, EMLX, vCard, ICS, MSG, Office 365, Live Exchange server, MBOX and etc.without any data losses. This tool exports selective OST files with a smart preview of all emails, contacts, calendars, notes, etc with FREE DEMO VERSION to user trial purpose which can help to recover items from every OST mailbox. It supports all MS Outlook versions up to and Windows versions.
MOre info- convert ost to pst manually