Within the phone/email area settings, you can specify whether to use this mapping to lookup constituents; whether or not to add new phone/email if a match is found; how to match and whether to mark existing matches as ‘inactive’
The setting selected above will update matched records. Alternately, a match can be added or ignored.
As some Raiser’s Edge Business Rules prevent multiples of the same phone type, users with those Business rules may find it helpful to either ignore the match altogether or to use the Field Setting on the Phone Type to ignore changes to existing phone types on existing constituents. You can read a bit more about these options in this Knowledgebase article.
For more information about the difference between an Area setting and a field setting, see this Knowledgebase article.