If you don’t have idea about the software which is best to do the data migration then there is one software which provides the free demo version of the data migration tool, the name of this tool is SysOZ OST to PST Converter you can try this tool for free and you will be able to recover the 30 emails form each folder. This software can save the data in to various different types of formats such as PST, EML, MSG, EMLX, vCal, vCard, MBOX. Apart from its support Office365 & Live Exchange Server and this is the only software which is able to do the migration of single as well as multiple files at a one time.
Read More: https://www.sysoz.com/products/ost-to-pst-converter.html
Read More: https://www.sysoz.com/products/ost-to-pst-converter.html