If you can choose the best duplicate Email remover for your inbox, then I can suggest the best tool for it becouse I'm also using it. You can try the TrustVare Email Duplicate Remover, which quickly removes duplicate Email form multiple files formate like OST, PST, MSG, EML, MBOX, etc without facing any issues. The software handles many duplicate Email files without downloading any other application. It can support all Windows OS versions like 11, 10, 8.1, 8, 7, and it also engages with email clients. It has an easy interface for non-technical users and they can simply operate it without any technical skills. Users can use a free demo version before buying this tool.