1. Open Thunderbird (Portable).
2. Right click on “Local Folders” on the left view pane.
3. In the context menu that appears Navigate to ImportExportTools> Import mbox file
4. On the “Files mbox import” menu select the second option “Import one or more mbox files, with its/their subdirectory” then click “OK”.
5. Navigate to the mbox file(s) you want to import select and click “Open”.
6. The mbox files should appear below the “Local Folders”.
7. Click on the folder will then show you the emails exported.