A multi-ring reliable messaging system is formed by interconnecting a plurality of token rings via a pair of gateways that includes an active gateway that is configured to communicate with the token rings and a standby gateway that also is configured to communicate with the token rings. The active gateway receives an original message via a first token ring, generates an associated message for a second token ring based on the original message, and propagates the associated message toward the second token ring. The active gateway supports total order delivery of messages within the token rings and causal-order delivery of messages between the token rings. The standby gateway monitors for original and associated messages received via the token rings in a manner for preventing loss of messages when the active gateway fails.