In the Online Market many tools for conversion but the best tool is eSoftTools OST to PST Converter software. This tool Import Outlook OST File to Windows 10 Mail. It can Support ANSI and Unicode format. It can Support ANSI and Unicode format. User have multiple formats to save OST file into PST, EML, MSG, MBOX, HTML, Gmail, vCard, Office 365 with all properties of email- to, cc, bcc, subject, time, date etc. it provides multiple file formats for OST file conversion like PST, EML, EMLX, MSG, HTML, and vCard.