Hi I am trying to import a list of contacts and some of these contacts are already in my contact list. However, Id like the new upload to add values into custom properties rather than replace them.
I.e. Lets say I already have a contact and the property Favorite_colours is listed as "red"
Then I upload another version of the contact which says the Favorite_colour is blue.
I want both Red and Blue to be there under the property. When I do the upload at the moment it just overwrites the Red and Puts Blue.