[common] What data (a piece of email or netnews, or a stream of
TCP/IP packets) 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. Readily verbed as blackhole: That router is blackholing
IDP packets.
Compare bit bucket and see
RBL.