The best duplicate item remover for Outlook is the
SysTools Outlook Duplicate Remover Software. It efficiently detects and removes duplicate emails, contacts, calendars, tasks, notes, and journals from PST/OST files without affecting original data integrity. The tool offers options to
remove duplicate emails in Outlook within folders or across folders, applies smart filters (date, subject, sender, etc.), and supports all Outlook versions. Whether duplicates are created due to syncing, importing, or profile issues, SysTools ensures a clean and organised mailbox quickly and safely — making it the most reliable choice for Outlook users.