If your OST files are corrupted or you want to convert them to PST, MBOX, and other file formats then the only tool I will suggest is the Sysinfo OST recovery software, which is one of the best tools when it comes to retrieving data from the corrupt OST Files. The Tool will easily convert them to PST, MBOX file format. No need to worry about how you will access it the tool has a very simple GUI which makes it easy to understand and use. The tool has more features some are mentioned below:

* Tool provides you with three different modes of recovery Standard, Advanced, and deep recovery modes.
* You can easily convert the recovered OST File to different file formats.
* Recover Outlook OST mail items like Email, Tasks, Calendar, Contacts, and Distribution Groups.

Access the tool: https://www.sysinfotools.com/recovery/o ... covery.php