Use the amazing ToolsGround PST Merge Tool to merge multiple PST files into one. Users can use the proposed method to load ANSI and Unicode PST files without modifying the original database. Emails, notes, tasks, contacts, calendars, and other data from multiple PST files can be easily merged. Users of this application can also successfully load password-protected PST files without modifying the original PST file. In addition, it provides a simple graphical interface (GUI) for non-technical users of the application. All Windows OS versions are compatible with the Merge PST Tool.
Get more information: https://www.toolsground.com/merge-outlook-pst/