Applies to: Exchange Server 2007 SP3, Exchange Server 2007 SP2, Exchange Server 2007 SP1
Topic Last Modified: 2007-07-03

Send connectors are configured on computers that are running Microsoft Exchange Server 2007 and that have Hub Transport and Edge Transport server roles installed. The Send Connector represents a logical gateway through which outbound messages are sent.

Exchange 2007 transport servers require Send connectors to deliver messages to the next hop on the way to their destination. A Send connector controls outbound connections from the sending server to the receiving server or destination e-mail system. By default, no explicit Send connectors are created when the Hub Transport server role or the Edge Transport server role is installed. However, implicit and invisible Send connectors that are automatically computed based on the Active Directory directory service site topology are used to route messages internally between Hub Transport servers. End-to-end mail flow is only possible after the Edge Transport server has been subscribed to the Active Directory site by using the Edge Subscription process. Other scenarios, such as an Internet-facing Hub Transport server or an unsubscribed Edge Transport server, require manual configuration of connectors to establish end-to-end mail flow.

During routing resolution, a Send connector, to which e-mail is routed for delivery to the destination address space, is selected. The Send connector whose address space most closely matches the recipient's e-mail address is selected. For example, an e-mail message addressed to would be routed through the connector that is configured to use the * address space. When you configure a Send connector for a particular address space, e-mail that is sent to that address space is always routed through that connector. Also, the configuration settings for that connector are always applied to e-mail sent to that address space.

Name and Status are the default headers. However, you can display additional headers by clicking View in the action pane, and then selecting Add/Remove Columns…. More headers are available for display on a Hub Transport server than an Edge Transport server. The only headers that are available for display on an Edge Transport server are Name and Status.


This field shows the display name of the Send connector.


This field shows whether the Send connector is enabled or disabled.

Authentication Mechanism

This field shows the authentication method that the connection is using. This column displays if the Send connector is configured to authenticate to a smart host.

DNS Routing Enabled

This field shows if DNS routing has been enabled on the Send connector.


This field shows the fully qualified domain name (FQDN) by which this Send connector represents itself in SMTP sessions.

Protocol Logging Level

This field shows if protocol logging is enabled for this Send connector. If protocol logging is enabled, the value is Verbose. If the protocol is disabled, the value is None.

Require Transport Layer Security (TLS)

This field shows if the Send connector requires authentication by a Transport Layer Security (TLS) certificate to identify mail sent from this connector.

Source Transport Servers

This field shows the Hub Transport servers that are associated with this Send connector.

Enable or Disable

To enable or disable the Send connector, click Disable or Enable.


To access the following tabs, in the result pane, select a Send connector, and then click Properties.

  • General   Use this tab to view display-only information about the Send connector and to maintain the protocol logging level and the connector's domain.

  • Address Space   Use this tab to add and maintain IP addresses and domains the Send connector will send mail for.

  • Network   Use this tab to specify how the Send connector routes e-mail messages, by using a domain name system (DNS) or using smart hosts.

  • Source Server   Use this tab to specify additional Hub Transport servers that can use this Send connector. The list of source servers can contain Hub Transport servers or subscribed Edge Transport servers, but not a mix of both. This tab is only available on Hub Transport servers.

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