You can clean duplicate item form large MBOX files quickly, try the best option like Softaken MBOX Duplicate Remover tool. The software automatically finds duplicates in the MBOX and removes them without losing important data. The tool has a simple interface for all non-technical uers and they can try it without technical knowledge. The software supports all Windows OS versions like 11, 10, 8.1, 8, and 7 without installing any other application. It will provied a free demo version before buying this tool.