A message tracker having a transfer monitor, a set of registers, and at least one arithmetic unit increases performance and reliability when transmitting or receiving messages within a computer system. A set of message parameters such as a current address, a remaining length, and a communicated length are stored within the set of registers. The transfer monitor observes data transfers on a multi-tenant bus in order to detect data transfers related to the message and provide an update signal. The message parameters within the registers are updated in response to the update signal. The process of detecting and updating is repeated until the entire message is transferred, and the message tracker then informs a control processor or process that communication of the message has occurred. To facilitate message coalescing, several message trackers may share a message queue that is configured to store message parameters corresponding to completed messages.