OLM converter software provided by Data Recovery Freeware is the professional tool to convert OLM data files. It helps users, who are looking for an easy method to convert their OLM data files with ease. It can also export password-encrypted OLM files to PST format with ease. Also, The Software Swiftly exports all email messages, contacts, calendars, etc. from OLM file format to another file formats. In the latest release, a lot of changes happened for making the product the best.
Source: http://www.datarecoveryfreeware.org/olm-converter-tool/