A method is disclosed for high-speed processing of structured application messages in a network device. According to one aspect, a network device receives a set of message classification rules that have been prepared beforehand by a system administrator or customer. The system analyzes the message classification rules to determine what part(s) of the message are necessary to classify a message according to the message classification rules. This allows the system to consider only the relevant parts of the message and ignore the rest of the message. The system extracts the portion of the message necessary for classifying the message and classifies the message using the values of the extracted information and the message classification rules. A unique sequence of operations is implied by the message classification and those operations must then be applied to the message.