Hi,
I've looked at all sorts of forums and have not been able to get this fixed.
I have one Exchange 2010 server working, and one Exchange 2013 server being installed, currently with two test mailboxes on it.
They are both on the same domain, in the same site, on the same physical network. They can Ping each and access each others resources. They both have no Firewall or Antivirus on them.
I have all default receive connectors on the Exchange 2013 server Enabled.
2013 can send and receive emails on the 2013 mailboxes on itself. It can also send and receive external emails.
But emails from 2010 to 2013 do not work. Weirdly they work from 2013 to 2010.
The Queue Viewer on Exchange 2010 comes up with an error:
451 4.4.0 Primary Target IP address responded with: "451 5.7.3 Cannot Achieve Exchange server Authentication." Attempted to failover to alternate host, but that did not succeed. Either there are no alternate hosts, or delivery failed to all
alternate hosts.
I have tried many posts to try and get the communication work, so no idea where to go. the issue (in my eyes) clearly lies with the receive connectors on the 2013 Exchange server..
I created another Receive Connector, Internal-Relay, as a Hub Transport, with:
Authentication settings of: TLS, Basic, BasicTLS, Exchange Server
Permission Groups: Exchange Servers, Legacy Exchange Servers
Scoping: Remote: both my Exchange servers
Scoping: Network Adapter Bindings: All Available IPv4 on port 25
FQDN: FQDN of the exchange 2013 server
and it is Enabled.
I also ran on my Cisco ASA 5510: no fixup protocol smtp 25
So I am not sure what to do..
Thanks