If you're thinking, "How do I convert PST to MBOX for free," I have a solution for you. Its name is eSoftTools PST to MBOX Converter Software. It's the most powerful tool I've ever used. The steps are straightforward and quick to implement. It shows a live preview of the PST file components before starting the conversion process. Both new and current users will try out the demo version. You can convert email items per folder for free in the tutorial edition.

Read more;- https://www.esofttools.com/blog/how-to-convert-pst-files-to-mbox-format/