WCF MSMQ - SRMP on a different port

Question

I have an application that pushes messages to a WCF endpoint via an MSMQ.

In dev, it works well when using the MSMQ protocol, but in production I need to do a network hop. I need to set this up so the queue pushes to the WCF endpoint over HTTP on a specific port (22200).

I thought this would work with SRMP, but it is not working. My outgoing MSMQ hangs with a message saying "Waiting to connect".

I've checked and I have access to the URL on the correct port.

How do I work out what the issue is?

Below is my client application configuration:

    <bindings>
  <netMsmqBinding>
    <binding name="NetMsmqBinding_IMyProjectReceiverService" exactlyOnce="false" timeToLive="00:01:00" queueTransferProtocol="SrmpSecure">
      <security mode="None" />
    </binding>
  </netMsmqBinding>
</bindings>
<client>
  <endpoint
    address="net.msmq://exampleuri.com:22200/private/MyProject.Receiver/v1/MyProjectReceiverService.svc"
    contract="IMyProjectReceiverService"
    binding="netMsmqBinding"
    bindingConfiguration="NetMsmqBinding_IMyProjectReceiverService"
    name="NetMsmqBinding_IMyProjectReceiverService" />
</client>