An email message returned to the sender by the receiving mail server. Messages are bounced because the recipient does not have an account on that mail server or the address is misspelled. If file attachments exceed a maximum limit, email can be bounced by either the sending or receiving mail server. Also called a "non-delivery receipt" (NDR), "non-delivery report" (NDR), "non-delivery notification" (NDN) or "delivery status notification" (DSN). See
email and
backscatter spam.