I have a new test interface that just came up today. We had generated a test ADT message on 7/22, and three more today (7/25), so there were four in the queue, waiting, as the thread kept retrying, wait for the vendor to configure their end. The thread was bounced several times during attempts at connection.
When the interface came up, the first message was sent third. The vendor confirms the order of delivery.
The message was delivered to other destinations via other outbound threads in the proper order.
What should I look at to determine the cause of this issue?