We have the following co-existence setup:
Edge 2013 sitting on the DMZ.
1 CAS 2013
1 MBX 2013
1 CAS/HUB 2010
1 MBX 2010
After creating a new edge subscription on the edge server and successfully completing it on the 2013 mbx server, when I run get-exchangeserver on the edgeserver I get only the 2010 CAS and the 2013 MBX. 2010 MBX and 2013 CAS are missing.
All mailflow is working fine, yet if I shutdown the 2010 CAS, incoming mail flow stops, because for the edge server the 2010 CAS is the nexthopdomain, it doesn't find it and gives a 4.4.1 error in the SMTP receive protocol logs.
I have tried re-creating the subscription several times, I tried forcefullsync, it syncs fine yet it does not discover all the servers.
The firewall on the edge is disabled and in the internal servers as well, just to be sure that there is no communication error.
When the edge server receives an email from the internet it sends it to the 2010 CAS/HUB server and then to the 2013 MBX server.
Also the documentation from technet states the following for Edge and messages arriving from external senders.
Mailbox server and Client Access server installed on different computers In this configuration, the Client Access server is bypassed for inbound mail flow. Mail flows from the Transport service on the Edge Transport server to the Transport service on the Mailbox server.
So in my config, the CAS should be bypassed, but yet that's not happening. The "proxy to a CAS server" option on the connectors is not enabled.
I believe all the above would be resolved, If I could make the Edge server discover all of the servers in the org.
Ideas?