I'm migrating from Exchange 2007 to 2013. I currently have two mailboxes moved to the Ex2013 environment simply for testing. We are using a Symantec.Cloud service for email encryption. I have my send connector configured with the Symantec smart host for outbound email and my outbound mail tests successfully.
I cutover my firewall to the Ex2013 server so I could test services before migrating the remaining mailboxes. Everything works except inbound mail. It's my understanding that the default receive connectors should be configured by default to receive mail. I have also contacted Symantec.Cloud to verify that they have no knowledge of our internal servers. MX records are pointed to them and they simply hand off to our public IP address. I verified that my NAT rules are in place so Ex07 and my Ex13 servers both resolve to the same outside IP address.
I can send internally between the two mailboxes that have been moved. I can also initiate a manual SMTP transaction from the command line and that delivers to my test mailboxes. So to be more specific it is the inbound mail FROM the outside world that does not work.
I've read other posts with mail flow issues and people are always asked to run the connectivity analyzer and test inbound or outbound email but obviously with the Symantec.Cloud service in place this option doesn't exactly work for my troubleshooting.
I do have split DNS but I've configured the appropriate DNS zone internally and I have successfully tested OWA, ECP, and Autodiscover internally and externally. Still no inbound mail flow from the outside world. I can also see in my firewall that my smtp rule is getting hits so Symantec.Cloud is still handing off email. What could I be missing that would prevent my Ex13 server from receiving email from the firewall? Also, if I go to my firewall and switch my inbound smtp rule back to the Ex07 server then try to send to my test mailboxes, that gets delivered successfully.