When a mailing is sent to a large number of constituents, often a few emails are suppressed. However, there is no easy way to see which constituents were suppressed. NXT only lists those who were not suppressed, to whom the email was sent, and then which of those addresses bounced. If the mailing includes hundreds, or even thousands, of constituents there are too many to manually check for the missing addresses. When mailings are sent which need to reach everyone, it is very helpful to know who has been suppressed and therefore hasn't received an email so that they can be contacted by other means.