Actually there's an interesting relationship between:
JMS_SPEC-91New "relaxed message order" option
JMS_SPEC-72 Poison message management
If a message is considered poisonous, all other messages from the same sender have to be moved to the dead letter queue as well, because message ordering would not be guaranteed if one of them is missing... even messages being sent later would have to get there. This is possible, but I'm quite sure this is not something every JMS provider has considered, when they implemented DLQs.
The only other way to stop poison messages from being delivered forever and still guaranteeing message ordering, would be to stop the destination entirely... which is not feasible.
With the relaxed rules, DLQs can be implemented more easily.
What do you think?
Rüdiger