You can try master solution of ost to pst converter open source tool. It is the right solution of ost export tool to import ost to pst file, OLM, Gmail, Office 365, live exchange server, EML, EMLX MSG, MBOX, HTML, vCard, vCal, olm, PDF, and, etc. The ost to pst file converter software to split large pst file. along with its tool to export file/folder from ost to pst file.