Answer: mailcar

AnswerCrossword Clue
MAILCARPart of some trains
MAILCARIt has a lot of letters
MAILCARLocation of letters on a train
MAILCARUsual objective of train robbers.
MAILCARPart of a train.
MAILCAROutlaw's target
MAILCARTrain part where sorting was once done
mailcara railway car specifically for carrying mail