Are you in trouble to convert MBOX files to PST for Outlook then you can try the MBOX File Converter that simply export MBOX files to PST with Attachments, Images, etc. The program can convert emails from MBOX to PST individually or all mbox files to PST at once. It also provides trial facility to perform the working process of the solution.
When I was in problem to export 2500+ MBOX files to PST then I got this solution from the google and firstly I tried it and then used for complete data migration from MBOX to PST. I achieved complete result from MBOX to PST so I am suggesting this solution to try it once and I hope it will also a complete solution for you. In free demo, it can export 20 emails from MBOX to PST without any cost. http://www.cubexsoft.com/mbox-to-pst/