Follow these steps to learn 'how to remove duplicate emails in Outlook.' To begin, launch MS Outlook on your Windows machine. Go to the "File" menu and immediately to "Info > Account Settings." As a result, the Account Settings box will appear. On that screen, choose the E-Mail tab and look for the specified account name. If it shows more than once, delete it right away. To delete the extra account, first choose the mail account and then click the "Remove" option. Finally, press the "Close" button. This will totally delete your duplicate account from Outlook.