Check the eSoftTools OST to PST Converter software. It very very good tool for all who want to convert Outlook OST file into PST. this tool easily converts Outlook OST file into PST and many other formats such as EML, HTML, EMLX, MBOX, Zimbra, Yahoo, Gmail, Office 365, ICS, MBOX, and vCard. It easily works in all Windows OS and MS Outlook versions such as 2019, 2016, 2013, 2010, 2007, and 2003. Check the free demo version of this tool and get 25 mailbox items from each folder.