How Connectors Are Created
previously mentioned, connectors must exist between all messaging
servers for SMTP traffic to be passed. However, inside the Active
Directory forest, you do not have to create and configure the
connectors between Hub Transport servers. These connections are created
implicitly. This means that the connections are created by computing a
path between AD sites that is based on Active Directory site link costs.
you install an Edge Transport server and a Hub Transport server, the
Edge Transport server must be subscribed to an Active Directory site by
using the Edge Transport subscription process. This process enables the
EdgeSync service to establish one-way replication of recipients and
configuration details from the AD directory service to the Active
Directory Application Mode (ADAM). This subscription process can be
accomplished quickly and easily by following the steps listed on the
Finalize Deployment tab on the Exchange Management Console. To get to
the Finalize Deployment tab, open the Exchange Management Console and
click on Microsoft Exchange in the console tree.
you subscribe the Edge Transpor server, data that is stored in Active
Directory gets replicated to the ADAM instance located on the Edge
Transport server. Some examples of the data that gets replicated are as
Connectors can be created using one of the following methods:
Explicit Active Directory Connector—
When an administratator creates a connector in the Exchange
organization, an explicit connector is created. This object can be
modified by the administrator and changes are replicated throughout the
Explicit ADAM Connector—
When an administrator creates a connector on an Edge Transport server,
it is stored in Active Directory Application Mode (ADAM). Connectors
that are created on Edge Transport servers are scoped to a single
server. An administrator can modify this object; however, the
configuration applies only to that particular connector on that Edge
Transport server only.
Implicit connectors are automatically computed using Active Directory
site link information and existing explicit Active Directory
connectors. This connector cannot be modified, and cannot be viewed
either in Active Directory or ADAM. The only way to change an implicit
connector is to make a change to the system topology. When a change to
the topology is made, the connector is recomputed.
Automatic Explicit ADAM Connector— When
you subscribe an Edge Transport server, the EdgeSync subscription
process creates an Automatic Explicit ADAM connector inside the
Exchange organization. This connector is then replicated to the ADAM
instance on the Edge Transport server. This connector cannot be
modified on the Edge Transport server, but can be modified in Active
Directory. Any changes made in Active Directory are replited to the
Edge Transport server during routine synchronization.
Automatic Implicit ADAM Connector—
All implicit connectors are computed from the system topology as
described previously. This applies to Automatic Implicit ADAM
connectors as well. One or more Edge Transport servers must have access
to the information contained in this connector. This connector cannot
be modified in Active Directory; however, if a change is made to the
system topology, the connector changes resulting from the topology
change will be replicated to the Edge Transport server during routine
the Edge Transport servers and the Hub Transport servers to communicate
with each other, they must be able to find each other using host
resolution in the domain name system (DNS).
Hub Transport Server Connectors
the Hub Transport server role has been installed on an Exchange Server
2007 server in your environment, you must configure the appropriate
Send and Receive Connectors. Until this has been accomplished, the
server will be unable to send SMTP messages to, or receive them from,
Send Connectors are
configured in the Exchange Management Console in the Organization
Configuration node, and are stored in AD as a configuration object. The
Send Connectors must be configured so that the Hub Tranport server
knows what source server to forward the message to. Bear in mind, there
can be multiple source servers configured on the connector.
Connectors, on the other hand, are configured in the Exchange
Management Console in the Server Configuration node, and are stored in
AD as a child object of the server. By default, when a Hub Transport
server is brought online, it has two default Receive Connectors already
Both Send and Receive
Connectors can be viewed and modified using the Exchange Management
Shell. As a matter of fact, many configuration settings can only be accomplished using the Exchange Management Shell.
SMTP Send Connectors handle outgoing messages; SMTP Receive Connectors
handle incoming messages. For proper message flow, the Hub Transport
server must have the appropriate
connectors to allow mail flow to and from the Internet (by relaying
through an Edge Transport server), as well as to and from other Hub
A Hub Transport server
must have at least three required connectors to function properly. The
first two, both of which are Receive Connectors, are created
automatically during the installation of the Hub Transport server:
Receive Connector that is configured to accept SMTP messages on port 25
from all remote IP addresses. The usage type for this connector should
be “Internal” as well. This connector is automatically generated during
the installation of the Hub Transport server.
second Receive Connector that is configured to accept messages on port
587 from all remote IP addresses. This connector is needed to accept
SMTP connections from non-MAPI clients who are connecting through a
client access server. The usage type for this connector should be set
to “Internal.” This connector is automatically created during the
installation of the Hub Transport server.
The third required connector is a Send Connector:
default, no explicit Send Connector exists on the Hub Transport server,
so you must perform one of two actions to create it—either the
connector is automatically generated when you create an Edge
subscription, or you must manually configure it. After this process has
been completed, your environment will be ready to route Internet-bound
messages from the Hub Transport server to the Edge Transport server,
and then out to the Internet.
Automatic Creation of Send Connectors
automatically create the Send Connector, you must have a server with
the Edge Transport server role and utilize an Edge subscription and the
EdgeSync service. To do so, perform the following steps:
Install the Hub Transport server role.
the Edge Transport server, export the Edge subscription file. If you
have more than one Edge Transport server, each server requires a
separate subscription file. The Edge subscription file can be exported
in the Microsoft Exchange Shell utilizing the following command:
new-edgesubscription – filename "c:\server1info.xml"
you must import the Edge subscription. This file can be accomplished
using either the Exchange Management Console or the Exchange Management
Shell. To do so using the Exchange Management Shell, run the following
command on the Hub Transport server:
new-edgesubscription –filename "c:\server1info.xml" –site "default-first-site-name"
that synchronization was successful by viewing the Event Viewer
application log and inspecting MsExchange EdgeSync events.
replicated to ADAM includes the Internet Send Connector. This connector
is stored in AD and the settings for it are written on the Edge
Transport server in the local ADAM instance. The connector has the Edge
Transport server as the source server, and is configured to use DNS MX
records to automatically route messages.
Manual Creation of Send Connectors
you decide not to use an Edge subscription, you must manually create
and configure the Send Connector. To do so, follow these steps:
Start the Exchange Management Console on the Hub Transport server.
In the console tree, expand the Organization Configuration node, and then select the Hub Transport node.
In the action pane, click New Send Connector. The New SMTP Send Connector Wizard starts.
the Introduction page, type a name for the connector, and then select
the intended usage from a drop-down box—the intended usage should be
set to Internal.
the Address Space page, click Add, and enter * (all domains) as the
address space. Leave the Include All Subdomains check box checked, and
click OK. Click Next to continue.
the Network Settings page, ensure the Route All Mail Through the
Following Smart Hosts option button is selected, and then click Add.
Enter the IP address or FQDN for the Edge Transport server, click OK, and then click Next to continue.
the Smart Host Security Settings page, select the Exchange Server
Authentication option button, and then click Next to continue.
Select one or more Hub Transport servers as the source for the connector, and then click Next.
Review the Configuration Summary, and then click New to create the connector.
From the Completion page, click Finish.
you must perform manual configuration of the required connectors on the
Edge Transport server. This information is covered in the next section.