bounce message A notification message returned to the sender by a site unable to relay {e-mail} to the intended recipient or the next link in a {bang path}. Reasons might include a nonexistent or misspelled user name or a {down} relay site. Bounce messages can themselves fail, with occasionally ugly results; see {sorcerer's apprentice mode} and {software laser}. The terms "bounce mail" and "barfmail" are also common. [{Jargon File}] (1994-11-29)