The top tool for removing duplicate emails in Outlook is
Regain Outlook Duplicate Remover. This sophisticated software effectively identifies and eliminates duplicate emails, contacts, calendars, and tasks from PST, OST, and BAK files. It is compatible with all versions of Outlook, such as 2021, 2019, 2016, and Outlook 365, and operates smoothly with large PST files. The tool provides various criteria, including subject, sender, and date, to accurately detect duplicates. Its intuitive interface allows all users to navigate easily, and a trial version is offered for free to examine its features prior to buying.