Don't need to panic, you can easily repair corrupted OST files, whether the file is corrupted due to Outlook or a server crash. I would recommend using FixVare OST Converter, which can easily repair corrupted or damaged OST files without losing data. It offers a selective data feature, which allows for repairing required data instead of entire OST files. It has multiple feature which makes it easy to use and, for better understanding, provides a free demo version for all users.