I recently received a collection of OLM files from an old Outlook for Mac account and need to access the email data again. The files contain several years of messages, attachments, contacts, and other mailbox folders. I no longer have access to the original Outlook profile, so I am looking for a practical way to read the OLM files and export the required data.

I initially assumed that an OLM file could be opened using a standard email application, but it appears to be more complicated because OLM is associated with Outlook for Mac. I also need some of the data in formats that are easier to archive or share, such as PDF, EML, or HTML. For another mailbox, I may need PST because the data will eventually be used with Outlook on Windows.

While researching different approaches, I found SysInfo Mac OLM Converter.  The software appears to provide a preview of OLM mailbox folders before conversion and supports exporting the data into several formats. It also mentions support for OLM files created by Outlook for Mac versions such as 2011, 2016, and 2019.

What I am trying to understand is whether using a dedicated OLM converter is actually necessary when the original Outlook installation is unavailable. I would also like to know whether converting the file changes the original OLM data or creates a separate copy during the export process.