I've been wanting to open my OST file in Outlook for quite some time, but I couldn't find any software that wouldn't damage the data in my OST file. So, I asked my brother, who recommended me to use eSoftTools OST to PST Converter Software, which I used, and it really didn't damage any of my OST file's data. 

Furthermore, this software also offers the option to convert OST files to Gmail, Yahoo, and Office 365. You can also use this tool to convert emails from OST files to Outlook in bulk. There's also a live preview option before converting, which allows you to see the OST file open live in Outlook. Using the included free trail, you can open up to 25 emails from OST files to Outlook for free.

Read More:- Open an OST file to Outlook