STEP 1: Start Outlook and click People in the lower left corner of the Outlook window. And, once exported you can import the new one to Outlook

Hence, the best way is to use export all the contacts to a new folder with the help of Outlook feature that excludes duplicates while exporting. You cannot delete thousands of duplicate contacts one by one as it will eat a lot of time and it is a very complex task to perform. Method 2: Export and Import Duplicate Contacts (if they are large in number) Multiple address books on Exchange: This is a scenario with many organizations that maintain several address books on their Exchange Server.which ultimately leads to duplication of contacts.

Contacts Synchronization: To find people easily and keep everything synchronized, you synchronize contact of Outlook with your laptop or mobile device and at times with social platforms like Facebook messenger, LinkedIn, Twitter, etc.

So, a new contact will be created for the same person.

Same person with different email accounts: Another reason for duplicate contact is when one user uses different email accounts with the same name.

It is a major cause of duplicate contact creation.

Message dragged to Contacts folder: If the email messages are dragged to Contacts folder, a new contact gets created in Outlook automatically.

The common reasons due to which duplicate contacts are created in Outlook 2016 are listed for you to understand the scenarios and avoid repeating them. Reasons Behind Duplicate Contacts in Outlook 2016 Hence, to resolve and remove duplicate contacts in Outlook we should first know the reasons behind the issue so that it can be prevented in the future. Unfortunately, there is no undo process to remove duplicate contacts instantly.

Delete duplicates in outlook calendar