I have a exchange 2010 server, we are migrating to 2013. The first test mailboxes that I have moved are not able to connect externally. I have verified the virtual directories and the certificate. But I keep getting the error " The action cannot be completed. The name cannot be matches to a name in the address list." When I try to access outlook externally. Then When I try to use the test connectivity website I get the error that "RPC proxy cannot be pinged". I have verified that all services are enabled for RPC and it looks like the cert is right. The firewall is open, what else could I be missing here?