Exchange 2013 in regards to Receive Connectors is really confusing me. It appears by default that it is basically an open relay. I'm showing it allowing any IP address to relay through it and had tested that internally through telnet. I than have issues with our spam filter getting connection refused when connecting to it, so I'm not sure whats going on. I created a separate send connector just for the Barraucda and set it to anonymous and ran the exchange shell command to really allow the anonymous logon and still get connection refused.