If you want to open your MBOX file in Outlook then you need complete information about manual and professional software. Because sometimes manual ways do not work then the third-party solution is the only hope.
Here you i would like to share some blogs where you read about the manual process of exporting mailbox from MBOX to PST and importing MBOX files into Outlook PST format at once.
Relevant Blogs:
https://www.mailsdaddy.com/blogs/import-mbox-outlook-full-accuracy/
https://www.mailsdaddy.com/blogs/best-method-open-mbox-file-withwithout-email-clients/
https://www.pling.com/p/1797804
https://www.podcasts.com/how-to-import-mbox-to-outlook
https://haikudeck.com/mbox-to-pst-converter-how-to-presentation-4a095ae174