MacSonik MBOX Converter for MAC  is a dependable and smooth  MAC software that can convert single and multiple files in a short period of time. It can convert MBOX files to PST, PDF, EML, EMLX, MSG, HTML, CSV, and TXT on Mac OS. it's a powerful GUI processor for easily converting your MBOX files.

There are both free and paid versions available.

Open MBOX files in Apple Mail 
1. On your Mac, open the Mail application.

2. In the File menu, select Import Mailboxes. 

3. In the new pane that appears, select Files in mbox format from the option list, and hit Continue.

4. In the next window that appears, navigate to your previously saved MBOX file, select it, and hit Choose. 

5. In a new window, Apple Mail will confirm where you can find the newly imported MBOX file, and you can select Done to close the window. 

Greetings,
Peter

 MacSonik PST Converter for Mac allows you to convert your pst file single as well as multiple files. like, converting pst to MBOX PDF, EML, EMLX, HTML, MSG, TXT, etc file formats. he Software is compatible with Mac OS 10.8 and above Versions.