The UnassignedCCTransactionNotificationBkg is used for sending email notifications to users. The email notification contains information about the credit card transactions attached to an expense report and the unattached credit card transactions that have not been used for a specified number of days.

You can use the UnassignedCCTransactionNotificationBkg.sendAtDaysTo{0} application parameter to configure the number of days after which the email notification must be sent.