What is the easiest way to open and read OST files?

The easiest way to open and read OST files is to use the SysInfo OST Viewer Tool, especially when Microsoft Outlook or the original Exchange/Microsoft 365 account is unavailable. The tool lets you directly load and preview OST files without requiring an active Outlook profile. You can view emails, attachments, contacts, calendars, notes, tasks, headers, MIME data, and RAW HTML while retaining the original mailbox folder structure. It supports both single and multiple OST files, including ANSI and Unicode files, and works with OST files from various Outlook and Exchange versions. The built-in Smart Search makes it easy to find specific emails using From, To, Subject, Date Range, and attachment filters. If you need to save the mailbox data, you can export it to PST, EML, MSG, PDF, MBOX, or CSV formats. The intuitive interface makes OST viewing simple for both technical and non-technical users.