I should also mention that the amqsputc DOS command works correctly. It puts a message on the remote server as I would expect. It is the .Net code where I am receiving the 2058 error.
I am trying to connect to a Win2k server running Websphere MQ. The queue manager's name is MQ_PORTAL. I have setup a server channel named CH1 and added the environment variable MQServer=CHL1/TCP/X.X ...