You can clean up duplicate Outlook data files without affecting your mailbox. The safest approach is to use a dedicated tool such as SameTools PST Duplicate Remover.  This software scans your PST files to detect and remove duplicate emails, contacts, tasks, notes, and calendar items while keeping your original mailbox data. You can choose to scan and clean specific folders or the entire PST file, depending on your needs. The tool ensures no data loss or corruption and maintains the folder structure of your Outlook files. Designed for all types of users, it requires no technical expertise and operates smoothly on all Windows versions, including 11, 10, 8.1, 8, and 7. You can use a free demo version.

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