A term which took on a new meaning during the early 90's when a "
disgruntled postal worker” took an automatic fire arm to work and mowed down everyone in sight. It was later discovered through poling and other scientific studies, that being a postal worker is the second most depressing job a person can have (next to dentistry). Now when you enter the post office you see a comparatively more
cheerful environment as I have noticed. The
workers play the radio loud and have pictures and
decorations up around their stations.
So basically, when someone is said to have "
gone postal" it either figuratively means that they got very angry and most probably yelled or it literally means they
opened fire with a gun on a mass of
innocent people.
Fun fun.