black hole
n.,vt.
[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.