Enumeration rejectMsgToSenderOnDiscardBehavior

Determines when to return negative acknowledgements (NACKs) to sending clients on message discards. Note that NACKs prevent the message from being delivered to any destination and Transacted Session commits to fail. Changes to this attribute are synchronized to HA mates and replication sites via config-sync. The default value is "when-queue-enabled". The allowed values and their meaning are:

"always" - Always return a negative acknowledgment (NACK) to the sending client on message discard.
"when-queue-enabled" - Only return a negative acknowledgment (NACK) to the sending client on message discard when the Queue is enabled.
"never" - Never return a negative acknowledgment (NACK) to the sending client on message discard.