Hi @Gopal4506 , welcome to the Community…! Yeah, if some other queue is full, and not configured to discard silently, then the publisher will get a NACk.
Just to be clear to all reading this thread: 99.99% of the time, you do NOT want the broker throwing away your Guaranteed messages. That’s essentially what can happen if you configure your queue to be Silent for the “Reject Messages to Sender on Discard”… even though my queue is full, doesn’t matter, don’t tell the publisher.
Why is your queue full?? This should only happen if your consumers are crashed out for a LONG time.
If this is development, why not configure the queue’s Max TTL to automatically clean it out after a day or a week or whatever?