For PST to Office 365 Migration you can use this third party utility PST to Office 365 Migration tool. This Software import & Upload PST Data to O365. This Software Import PST to Office 365 with all emails, calendars, contacts, etc in just a few clicks. This Software also provide free trial version where you can check the performance of this tool. You can also see the preview of all emails before the conversion. Use free trial version and see the original results.