1. n. A piece of email containing
live data intended to do nefarious things to the recipient's
machine or terminal. It used to be possible, for example, to send
letterbombs that would lock up some specific kinds of terminals when
they are viewed, so thoroughly that the user must cycle power (see
cycle, sense 3) to unwedge them. Under Unix, a letterbomb can
also try to get part of its contents interpreted as a shell command
to the mailer. The results of this could range from silly to
tragic; fortunately it has been some years since any of the standard
Unix/Internet mail software was vulnerable to such an attack
(though, as the Melissa virus attack demonstrated in early 1999,
Microsoft systems can have serious problems). See also
Trojan horse; compare nastygram. 2. Loosely, a
mailbomb.
