To convert your Mac OLM files to PST format I would suggest you Mac OLM Converter. The tool can easily convert multiple OLM files to PST format including HTML formatting, Attachments, Images, Links, and etc. The software is designed to be used by all types of users, those with technical knowledge and those who are not technical and beginners; everyone can operate this tool easily. It supports all versions of MS Outlook and Mac versions.https://www.kdetools.com/mac/olm/