Removing duplicated contacts is a manual process. The following article contain instructions on the best way to remove duplicates.
1. Open your Outlook 2010 and click on the contacts tab.
2. Select the contacts folder that has duplicate contacts.
3. Within the View tab, click Change View, and then select Phone. This is the best view to scan your contacts list and see the duplicate contacts.
4. Located in the View tab, click View Settings.
5. Click Columns, and then in the Select available columns from list, click Frequently used fields.
6. In the Available fields list, click Modified, and then click Add.
7. Click Move Up until Modified is at the top of the Show these fields in this order list.
8. Click OK twice.