Set the property com.openexchange.import.contacts.limit to import.properties to limit the maximum number of contacts imported. All excess contacts will not be imported.
# sets the limit on how many contacts can be imported at once
# -1 means unlimited, defaults to -1
#com.openexchange.import.contacts.limit=-1
# sets the limit on how many contacts can be imported at once
# -1 means unlimited, defaults to -1
#com.openexchange.import.contacts.limit=-1