You can use the Softaken MSG to MBOX Converter Tool to convert bulk MSG emails to MBOX format because this software has a simple graphic user interface so you will get a simple process to convert bulk MSG emails to MBOX format without error. This is the best tool that supports all versions of Outlook and connects with Thunderbird, Apple Mail, and Entourage without installation. This application has a simple graphic user interface to convert MSG files into MBOX without error Get a free trial to convert a few MSG emails to MBOX then Install it on Windows 11, 10, 8.1,8, 7, XP, and Vista, operating systems.
More Info: https://www.softakensoftware.com/msg-to-mbox-converter.html