Hello @NasdaqMickelson ,
I looked into this last night but so far have been unable reproduce the issue as you describe. I was inducing errors in a number of different ways such as shutting down ingress on the queue or allowing it to exceed the maximum message size configured for the queue. However, I did not experiment with very large attachments (>30MB) so will attempt that next.
I am curious if the situation you are observing is a rejection by the broker, or merely a failed send. Are you checking the return code of ISession.Send(…) ? Can you verify the queue received but rejected the message by going into the Broker Manager UI, Queues > { Queue Name } > Stats under the section “Incoming Messages Not Queued”?
One final question, does your SendMessage() method actually return Task.CompletedTask or is that a workaround because of your issue? (Presumably you meant completionSource.Task , correct?)