If you want to convert OST to PST Outlook then you can use the master utility name of Microsoft ost to pst converter online free that provides multiple features facilities for converting. By using Its application all Most users convert OST to PST files in such a case.
Here's how to convert OST to PST Outlook online Freeware-
Start OST Viewer Pro and select the .eml files to convert.
Click the "Export" button.
Choose the conversion format (PDF,Zimbra, MBOX, Office 365, Live Exchange Server, EML, EMLX, vCarde, and etc.)
Split option.
Messages filtering option.
Here's how to convert OST to PST Outlook online Freeware-
Start OST Viewer Pro and select the .eml files to convert.
Click the "Export" button.
Choose the conversion format (PDF,Zimbra, MBOX, Office 365, Live Exchange Server, EML, EMLX, vCarde, and etc.)
Split option.
Messages filtering option.