jmsTemplate , DefaultMessageListenerContainer and JMS transaction manager

Hello:

My application runs in a non-transacted enviroment

I would like to know if a JMS session is not transated but it's auto-acknowledge , it allows redelivering the non-acknowledge messages

I've got a broker in non-persistent mode and I would like t know if it's required to use transactions for ensuring the delivery


Because I'm looking information about transacted session and :

1) jmsTemplate requires sessionTransacted = true
2) DefaultMessageListenerContainer requires a JMS Transaction Manager

I don't understand the difference between producers (jmsTemplate ) and consumers

And I don't understand why to use auto-acknowledge in a non-transacted session

I'm confuse

Thanks and regards