You can use MailsDaddy Free PST Viewer to open and read Outlook PST files without installing Microsoft Outlook. It lets you preview emails, attachments, contacts, calendars, and other mailbox items while preserving the original folder structure. The tool supports ANSI and Unicode PST files and provides read-only access to help keep the original PST data unchanged. It is a convenient option for viewing archived emails, backup files, and old Outlook mailbox data on Windows.