If you are searching to view, convert, and read OST files without Outlook on Mac then you must useMacSonik OST Viewer Tool. This software is capable of converting and saving OST files into PDF, DOC, MBOX, and other file formats. Using this tool you can convert OST email ranges between specific dates. The users only have to select a start and an end date for the files/folders, and the tool will start converting files into the selected format.