Try the eSoftTools OST to PST Converter software to convert the OST file. It's a most famous Outlook conversion tool. It's easily work in all Windows OS and MS Outlook versions like 2019, 2013, 2016, 2007, 2003, and 2010. Its provide many types of different file formats to convert OST file such as EML, EMLX, HTML,MSG, Office 365, Gmail, Yahoo, Zimbra, ICS, and vCard. Check the free demo version of this tool and get 25 mailbox items from each folder.
Read more- Convert the OST file
I will suggest you to use the Sysinspire OST to PST file Converter software,this software is easy to use for technical and non-technical users and it supports all types of OS windows including window 11.this software provides you free demo version to save the 25 file items from each and every folder of the OST mailbox and it converts the OST file into PST,EML,EMLX,MSG,MBOX,HTML,vCard and office 365.You can download the software from official website.
Read More:- Import an OST File in Outlook Office 365