There are many methods and ways for Outlook duplicate email remover, but I can suggest the best tool becouse I'm also using it. Try the TrustVare Outlook Duplicate Remover. This tool automatically scans Outlook files like email, contacts, notes, tasks, events, calendar, etc, finds duplicate items and removes them without losing original data and after removing duplicate files, it will save your time efforts, and keeps mailbox clean. It has an easy users-friendly interface for non-technical and they don't need any technical skills to use this tool. The software works with all Windows OS versions, like 11, 10, 8.1, 8, and 7. There is no need to install MS Outlook. It will provide a free demo version before buying this tool.