Third party solutions are always satisfying. They always provide better results and are the less time-consuming process. For converting MBOX to Outlook PST, you can refer MailPro+ MBOX to PST Converter. The best thing about this utility is that you can try its demo version as well.
Refer: http://www.mailproplus.com/email-conversion/mbox/pst.html
There is no secure manual method to import MBOX data to Outlook. Therefore, we suggest adopting MBOX to Outlook converter to migrate MBOX data into PST format in few simple clicks. The software is specially designed to maintain the message body, header text and meta data without any error.