Download the MBOX Viewer Tool and install it on your system. Run the tool as an administrator.

On the opening panel, you can specify the saving path for the Log file and Temp File.

Choose either of the two given options: Select File/Multiple Files and Select Folder. Click Next.

Click on the Select File(s) button to add single or multiple MBOX files. To select an entire folder, click on Select Folder.

Locate the folder with the MBOX file, select the files you need to open, and click Open.

After MBOX files are added to the list, you can remove any using the Remove or Remove All option.

Once you click Next a pop-up appears with the 'Import Successful. Please Expand the Tree Hierarchy.' message. Click Ok to proceed.

Next, expand the file hierarchy to see MBOX content and attachments.

Double-click on any MBOX file to see all emails present in it. To read the email messages, double-click on the email.

Further, if you want to save these MBOX files, tick the checkboxes in the left panel to select files. Click Next.

To save, choose an appropriate format from the given list. Say, we choose PDF.

You can also apply additional options and filters to enhance the output. Select Remove duplicate, date filter, and more.

Lastly, click on Convert to begin MBOX File conversion to your desired file format.

Once the MBOX file conversion is complete, click Ok. To download the conversion report, click on Download Report.