I personally recommend this ost to pst converter software to easily convert all OST files into PST. With this software, you can easily convert multiple OST files to Outlook PST file format with including all emails, contacts, calendars, and etc. It allows to batch conversion of OST files to PST file format with attachments. you can also try this Software free demo version before buying this Software. Visit here for more info:-
There are multiple third-party tools available on the internet, you just need to find the right solution. I have used DataVare OST to PST Conversion tool when I required the same issue and got the accurate result. It supports OS Window, windows10, XP, Vista, 8, 8.1, etc. A free demo version of this tool is also available few emails can easily be converted into each format.
By taking the help ATS OST to PST Converter you can export the single as well as multiple files along with email, contact, attachment, notes, etc. With the help of this program you will be able to export password protected and encrypted file. The program is designed with latest design and algorithm and many more. It has many features that make the conversion process smooth and reliable.
Before finishing the conversion process, it will show the preview of the recovered mailbox along with all the data of OST file. You can make changes in the database but before the actual conversion. It does not make any changes in the database and provide an accurate result. It support MS Outlook version 2019, 2016, 2013, 2010 and all the below version.
Read More Info:https://ats-ost-to-pst-converter-toolkit.en.softonic.com/