If you want to transfer MBOX files to Office 365 then you can try Aryson MBOX to Office 365 Migration tool. This software imports MBOX files into Office 365, Gmail, Thunderbird, Hotmail, and other email clients. The software maintains the data integrity and folder hierarchy during the process of migration. You can preview the all emails of MBOX files before migrating to Office 365. It offers a user-friendly interface.
Read More: https://www.arysontechnologies.com/mbox-to-office-365/