If you want an easy way to add MSG files into Outlook. I recommend using the DailySoft MSG Converter Tool to change MSG files to PST format. This tool uses advanced formulas, making it very fast and effective in its area. The tool has a few features that help users with changes. The tool has a preview option that lets you choose the right data for change. Users are able to access the tool to convert up to 25 exports per folder for free and test its speed. The tool works with all versions of Windows.
https://www.dailysoft.org/msg/pst/