I would like to suggest you this third party tool Regain OST to PST Converter software where you can easily Convert OST to PST with all emails items like: emails, attachments, contacts, notes, calender and journals etc. this software also save OST file to PST, EML, MSG, MBOX, HTML, ICS, VCARD formats. You can see the Preview of Scanned Emails in Preview items before Conversion. you can also try this software free trial version at free of cost.