A system and method for flexibly managing heterogeneous message delivery. A message is queued. The message includes an identifier and content in intermediate format pending delivery through type-specific message interfaces. The delivery of the message to a recipient is managed with the message cast into one of a plurality of message types. The identifier is formatted and the content of the message is structured from the intermediate format into one such message type for the recipient. The message is sent to the recipient via the message interface corresponding to the selected message type. The delivery of the message is tracked by monitoring an acknowledgement of a receipt of the message by the recipient. An alternate message type available is selected upon non-acknowledgment of message receipt.