With this eSoftTools OST to PST Converter software, you can easily convert OST files to PST files for free. Sent Items, Calendars, Tasks, Notes, Inbox-Outbox items, Drafts, E-mails, Chats, Contacts, Appointments, and Journal Folders can all be recovered with this software. Selective conversion is a feature of this software that allows you to pick and select the files and folders you wish to convert before converting them to the format you want. Check the tool's ability by using the free trial version.
For more info- Convert OST to PST file
For more info- Convert OST to PST file