RabbitMQ - your local machine will connect out to it, and some other service sitting outside the firewall will connect in to rabbitMQ, RabbitMQ wil then transfer the messages through between the client and your server.
I often have a front-end server sitting in the cloud and have the backbend service running on my Mac, as long as my backbend service can connect to the queue, and the front-end service can connect to the same queue, you're sorted.