To delete repeated emails in a PST file while keeping all your data safe, you can use a dedicated tool like SameTools PST Duplicate Remover. This software scans the entire PST file, detects duplicates based on emails, contacts, notes, tasks, calendars, etc, and removes only the repeated copies while keeping the original emails intact. It maintains the folder structure, attachments, and metadata during the cleanup process without downloading any other software. The tool manages a huge number of duplicate PST files without facing any glitches. It will support all Windows OS versions like 11, 10, 8.1, 8, and 7. It has an easy interface for both technical and non-technical users. A free trial is available, so you can try the tool.