To receive and send electronic messages, the system uses incoming and outgoing queues. Every installation of Supply Chain Integrator has two queues, and they are all unique. Isah uses Microsoft Messaging Queues, which you need to activate in your OS, as documented. There should be no need to access the Microsoft Messaging Queue directly, because the web interface shows all messages that have been sent and received.
If you do want to see the queues in the Microsoft environment, follow these steps:
You now see your queues, and when you open one and select Queue Messages, you will see the number of messages that are now in the queue. This number will mostly be '0', because messages get imported and sent every minute.