By Using outlook ost file converter tool you can single as well as multiple OST files into Outlook PST file format. There is an option to convert your OST file to multiple file formats, including PST, Office 365 account, pst file, EML, EMLX, MSG, HTML, MHTML, MBOX, VCF, CSV, ICS, Live, Exchange Server, Zimbra, Gmail, Yahoo, and etc. This tool has a user interface that makes it easy to use for everyone.