[zheng]

Most systems I know which require this just do at-least once on the sending side and dedupe on the receiving side. If you build this into your framework, to applications you have exactly-once barring unbounded partitions and the like.

[tupshin]

This works only so long as the receiving side is able to retain all messages (or message ids if those are guaranteed to uniquely reference a given payload). It does not work for outages of unbounded (or otherwise impractical) data size or duration.