Please note that the import/export function is currently not available in new Outlook for Mac. If you use New Outlook on Mac, you may wish to temporarily revert to Classic/Legacy Outlook to perform import/export functions.
You can only export Mac Outlook items as an .olm file, which can only be imported into Outlook on Mac, or with third-party software if it’s on another app.
Learn more about how to import/export/archive all your files in Outlook for Mac.