Convert MAC OLM to PST format, I suggest an effective tool Kernel for OLM to PST Converter Tool. The tool quickly and safely converts all email items like email items including email, attachment, contact, calendar etc. After conversions the software saved different formats such as PST, MSG, EML, MBOX, IMAP, RTF, TXT, MHTML, HTML and DBX. It supports all versions of MS Outlook and Windows OS versions. Reference link -
http://www.olmtopstconversion.net