The third-party software for converting mbox files is the best option compared to the manual method. The eSoftTools MBOX Converter tool is the best solution for it. It can support all email clients that file save in. mbox, .mbx, .mbs, and. sbd formats. Single or bulk mbox files may be converter to MSG, EML, EMLX, HTML, NSF, Office365, Yahoo, and Gmail. The tool can also show a live preview of the mbox mailbox and folder before conversion. You can download the free demo pack from its official website, which converts the initial 25 items from each mbox to other file formats.
For more info:- Convert MBOX to PST files