I would like to suggest
OST to PST Converter Software to transfer OST to PST files format. It supports both ANSI and UNICODE and moves multiple OST files in one PST file without any data loss. It gives a smart preview of OST files to PST files. The software is a Windows-based application that supports to run on all Windows operating system such as Win 10, 7, XP, Vista, etc.
Visit here: https://www.ostfileexporter.com/ost-converter/pst/
