Hi!
I just tried to configure domain security in Exchange 2013 in a test environment: two messaging organizations, each running a dedicated client access role and a mailbox server role.
Domain security seems to be configured correctly - recipients running Outlook get that additional icon which says that the email 'was received securely'. In that scenario the mailbox server is sending the mail directly to the recipient domain. So no proxying via the local client access server takes place.
When I try to use the domain local CAS as proxy (Set-SendConnector -FrontendProxyEnabled $true) the mail stays in the mail queue. The LastError on the queue states: '... 451 4.7.3 The admin has temporarily disallowed this secure domain...'. The protocol log of the send connector states: 'Message to secure domain 'dom1.test' on send connector 'Outbound Proxy Internal Send Connector' failed because DomainSecureEnabled was set to false.'
I have no clue where that internal send connector could be configured. Or where the 'Outbound Proxy Internal Send Connector' can be seen.
Or is domain security just supported without using the frontend proxy?
Many thanks in advance!
Greetings,
Nils