black hole

n. What a piece of email or netnews has fallen into if it disappears mysteriously between its origin and destination sites (that is, without returning a bounce message). "I think there's a black hole at foovax!" conveys suspicion that site foovax has been dropping a lot of stuff on the floor lately (see drop on the floor). The implied metaphor of email as interstellar travel is interesting in itself. Compare bit bucket.