If you don’t see any files with the extension mbox, then it’s the ones without an extension. The mbox files are found in your Thunderbirds profile folder (usually in the mail -> local folders).

This handy program is used to convert Thunderbird’s mbox email files into eml files. It’s a free Windows application that has a built in tool called mbox2eml. The first thing you’ll need is a program called IMAPSize. Outlook doesn’t directly import Thunderbirds email, however with the right tools, and some time, it can be done. No, Thunderbird doesn’t have an import function for the PST file, but it can import anything that’s in Outlook on the same machine. Then, when you setup Thunderbird it will ask you if you want to import your Outlook email. The first thing you need is all your email in Outlook. Exporting it from Thunderbird and importing in to Outlook is not hard either, just time consuming. The process of exporting email from Outlook to Thunderbird on Windows is really easy.

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