Microsoft Office Outlook comes with an inbuilt feature which helps you in finding if an email is already existing with any other contact when you add a new one. In order to enable this you need to check the label which says “Check for Duplicates when saving new contacts” which is available in Options > Contacts under Naming and Filing heading.
This way you not only keep your Contact Book much organized but also can easily detect duplicate contacts and keep an already existing updated.
