Trying to setup a receive connector to relay mail that would have a more restricted RemoteIPRange. According to Technet, you can have multiple recieve connectors on the same IP/Port combination as long as the RemoteIPRange overlap, the most restrictive will be used.
So I setup a receive connector restricted to 2 server IPs but on the same port (25) as the Default FrontEnd Connector (single server environment). The 2 servers would work fine and connect to the new Send Connector. However, the Default Frontend EXCH01 would stop recieving traffic, which has a IP range of 0.0.0.0 Any connections from other servers would get the following message on connecting: 421 4.3.2 Service not available. So for the time being, I've moved the receive connector to for relaying to port 26 and everything is working.
Is there something in the configuration of a receive connector that I'm missing. I know i've done this on Exchange 2010 without issue.