The best option to create a backup of the Mac OLM file in PST format is to use SameTools to Convert OLM into PST. This allows users to safely return all their Mac Outlook data, including email & attachments, which can be accessed in PST files in Windows Outlook. Also prevents data loss while preserving the original folder organization and email formatting. With its simple steps, anyone can quickly create a reliable backup of OLM files into PST. It is suitable for both Windows OS & Outlook editions. Furthermore, this application also provides a free demo version to test before full use.
Read more; https://www.sametools.com/convert/olm/