If you want to migrate a PST file to MBOX, you should try the KDETools PST to MBOX Converter program which can simply change Spicebird, SeaMonkey, Thunderbird, Apple Mail, etc. The tool safely converts email items, attachments, contacts, calendars, etc. .PST file formats like PST, MBOX, HTML, PDF, MSG, EMLX. It also offers the solution to restore and export PST to Office 365, Live Exchange Server.

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