You can also try Mac OLM Converter, another all-in-one solution that allows to convert OLM to PST, PDF, MSG, EML, MBOX, NSF, Office 365 and more. It also provides you the filter option which helps you to find the specific mail by date range, subject and other attributes. You can also preview the files before you convert them. It guarantees 100% data safety and assures no data loss or file modification.