You can easily convert Mac DBX files to MBOX using MacUncle DBX to MBOX Converter. The tool supports Mac OS Machines.
Start MacUncle DBX to MBOX Converter on your Mac Computer.
Select DBX file using Add File(s) or Add Folder(s).
Choose DBX files or folder as per need and then press Next button.
From Select Saving Option choose the MBOX format.
Confirm default destination path or browse different destination path and click on the Export button.
In few moments you will the software will give notification about the DBX to PST Conversion completion.