I attempted to open a PST file in Thunderbird but was unable to do so. One of my friends, on the other hand, suggested that I use the eSoftTools PST to MBOX Converter (https://www.esofttools.com/pst-to-mbox-converter.html) Software. He claims that using this software, you can easily convert an Outlook PST file to an MBOX file, and that it supports Outlook 2019, 2016, 2013, 2010, 2007, and previous versions.
Get more information:- Open PST File in Thunderbird (https://www.esofttools.com/blog/how-to-convert-pst-files-to-mbox-format/)