If you are looking for an easy solution to transfer MBOX emails to Thunderbird then try
Advik MBOX Converter tool on your system. The software can
import MBOX to Thunderbird in just few simple clicks. It is a standalone utility which means you do not need to install any other applications to complete the importing process. With this utility, you can import multiple MBOX files at once. In this tool, you just need to add MBOX file and choose Thunderbird as saving option. It will transfer MBOX file into Thunderbird in just few seconds.
Steps to Import MBOX to Thunderbird
1. Run the tool and add .mbox file.
2. Choose mailbox folders.
3. Select Thunderbird as a saving option.
4. Click Convert button to begin the importing process.
The importing process is complete!