If you want to quickly remove duplicates in Outlook PST file, then I recently used SysTools Outlook Duplicate Remover Tool, I think it's best because it automatically deletes all redundant items from the mailbox. Talking about duplicate items like emails, notes, contacts, calendar, etc. This proactive tool allows users to save both time & effort as it batch removes the items. Users may simplify their PST files, optimise storage, and improve system performance by utilising PST Duplicate Remover software. Use the free demo version of this programme to learn more about the tool's features and capabilities.