In the initial settings, only one email will be sent. If the same email address is found, the information with the more recent date received will be used for sending. However, if the date received is the same or not set, there is no way to select which card will be used for sending. If there are multiple business cards of the same person, and you would like to specify which one you would like to send to, remove the tag from the card you would not like to send to.