Systems, methods, and other embodiments associated with a message recognition system configurable to define new message formats and interpret electronic transaction messages are described. In one embodiment, a method includes analyzing an electronic transaction message received from a remote device to determine a message type of the electronic transaction message. A message type data structure is queried to determine whether the message type is defined in the message type data structure. A message type configuration interface comprising one or more input fields for defining the message type is generated. Parameters are received via the one or more input fields of the message type configuration interface, and a message type definition is generated based upon the one or more parameters. The message type data structure is reconfigured to include the message type definition.