Finding effective ways to open OST files on Mac? Try the Cigati OST Viewer. It is safe and trusted by many professionals. The tool saves the OST file to various file formats and email clients, including PST, MBOX, CSV, EML, Gmail, Thunderbird, and IMAP. It not only alters the original data but also maintains the folder hierarchy. The filter option allows the user to filter the unwanted emails and select the emails by date range. This tool allows you to open OST files on Mac effortlessly. Visit the website for more information.