I have used many conversion programs, but I found the best and safest KDETools PST to MBOX Converter Software, so I will tell you to choose this software and convert multiple files. The tool is compatible with all PST Thunderbird, Apple Mail, Pocomail email client applications. Eudora, Spicebird, Entourage, Google takeout, Netscape, SeaMonkey, etc. This software supports the selective function that is used to export items and folders from PST files to MBOX.

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