For contacts, 1-Click Duplicate Delete for Outlook can do more than simply delete: It can merge similar objects. This is done automatically (unless you use the advanced scan and turn this feature off).
The contact is broken down into its individual information pieces. Identical pieces remain the some, the ones missing are copied. If conflicting data is present for one data field, then (by default) the newer version will be used and the older one appended in brackets. This way nothing gets lost.
Note about the Advanced scan:
During the "Advanced scan" you will receive a list of duplicates and may choose which version to keep. Of course this does not mean that the other versions are simply ignored and deleted. Instead the software will use the data wherever possible. But your choice determines which version is the best if the software has competing values for a field. The other versions will be appended with the text "old:" behind the best version (if you haven't deactivated this and if the field allows such a text.)
Example:
Contact 1 (new) |
Contact 2 (old) |
Will be merged to |
Peter Miller |
Peter Miller |
|
Tel: 555-1234567 |
Tel: 555-1234567 |
|
Acme Inc |
Acme Ltd |
Acme Inc (old: Acme Ltd) |
1/1/2010 |
1/1/1980 |
1/1/2010 |