You can easily open & read OST files on Mac OS using MacUncle OST Splitter. The tool supports Mac OS Machines.
Start MacUncle OST Splitter on your Mac Computer.
Select Outlook OST file using Add File(s) or Add Folder(s).
Click the Save button in the menu ribbon and configure the required fields.
Press the OK button to complete the process and receive the OST files in a smaller, split format.