Yes, you can transfer an MBOX file to Yahoo Mail without using Thunderbird by using Advik MBOX Converter. This professional tool allows you to directly import MBOX to Yahoo Mail  without any email client dependency. Advik MBOX Converter securely connects to your Yahoo account and transfers emails along with attachments, folder hierarchy, and email metadata.

Steps to Transfer MBOX File to Yahoo Mail Using Advik MBOX Converter:

1. Download and install Advik MBOX Converter on your system.

2. Launch the software and add the MBOX file or select the folder containing MBOX files.

3. Choose Yahoo Mail as the export or destination option.

4. Enter your Yahoo Mail login credentials for authentication.

5. Apply filters or select specific folders if required.

6. Click Convert to start importing MBOX emails into Yahoo Mail.