Share via

Configure Send Connector Properties


Applies to: Exchange Server 2010 SP3, Exchange Server 2010 SP2

Send connectors create a logical connection to remote e-mail systems and are responsible for outbound transmission of e-mail messages. If you use the EdgeSync process, it configures the Send connectors required for mail flow to the Internet, and to the Edge Transport servers in your Microsoft Exchange organization. If your organization requires a Send connector with specific configuration options, or if you don't use the EdgeSync process, you must manually configure Send connectors.


Don't perform this procedure on an Edge Transport server that has been subscribed to the Exchange organization by using EdgeSync. Instead, make the changes on the Hub Transport server. The changes are then replicated to the Edge Transport server next time EdgeSync synchronization occurs.

Looking for other management tasks related to transport servers? Check out Managing Transport Servers.


  • Send connector. For detailed steps about creating a new Send connector, see Create an SMTP Send Connector.

  • You should determine the specific usage for this Send connector so you can correctly configure its properties. To learn more about Send connectors, see Understanding Send Connectors.

What Do You Want to Do?

  • Use the EMC to configure the properties of a Send connector

  • Use the Shell to configure the properties of a Send connector

Use the EMC to configure the properties of a Send connector

You need to be assigned permissions before you can perform this procedure. To see what permissions you need, see the "Send connectors" entry in the Transport Permissions topic.

  1. If you're configuring a Send connector on a Hub Transport server, in the console tree, navigate to Organization Configuration > Hub Transport. On an Edge Transport server, select Edge Transport in the console tree.

  2. In the work pane, select the Send Connectors tab on the right, and then double-click the Send connector you want to configure.

  3. Use the General tab to modify the general properties of the Send connector:

    • Connector name   To rename the connector, type a new name in the connector name field, and then click Apply.

    • Connector status   This field shows whether the connector is enabled or disabled. You can't change a connector's status from the properties page. You need to use the Enable or Disable actions in the EMC or the corresponding Shell commands. For detailed steps about enabling or disabling Send connectors, see Enable or Disable a Send Connector.

    • Modified   This field shows the last date that the connector settings were modified.

    • Protocol logging level   Use this pull-down list to select the protocol logging level. Select None to turn off protocol logging. Select Verbose to turn on protocol logging.

    • Specify the FQDN this connector will provide in response to HELO or EHLO   When a transport server uses this Send connector to transmit outbound messages, it needs to establish an SMTP connection to the destination messaging server. This field specifies the fully qualified domain name (FQDN) used in that SMTP connection to identify the source server. The value of this field is displayed to the destination messaging servers whenever a source server name is required. To learn more about how the value of this field is used, see Understanding Send Connectors.

    • Maximum message size (KB)   To set a maximum message size for messages that can pass through this connector, select the check box, and then enter a value in KB in the adjacent field. The valid input range is from 0 through 2147483647 KB. To remove any restriction on the maximum message size, clear the check box next to Maximum message size (KB).

  4. Use the Address Space tab to maintain the list of address spaces for which this Send connector is responsible.

    You can configure either an SMTP address space or a custom address space. Custom address spaces may only be configured on Send connectors that exist on Hub Transport servers. If you use a custom address space type, you must use a smart host to route e-mail.


    Although you can configure custom address spaces on a Send connector, the Hub Transport server still uses SMTP as the transport mechanism to send messages to other messaging servers using this Send connector. To send messages to messaging servers that don't use SMTP as their primary transport mechanism, such as a third-party fax gateway server, you must use a Foreign connector. For more information about Foreign connectors, see Understanding Foreign Connectors.

    To configure an address space, do the following:

    • Add   To specify an address space for which this Send connector is responsible, click Add or the drop-down arrow located next to Add. If you click Add, the address space type is SMTP. If you click the drop-down arrow located next to Add, you can select SMTP Address Space or Custom Address Space. For each new address space, you need to configure the following:

      Type   This field describes the address space that you enter in the Address field. If you clicked Add, this field is set to SMTP and is unavailable.

      Address Specify the address space for the Send connector. If you entered SMTP or X400 in the Type field, Exchange verifies the syntax of the address space that you enter. Exchange can't verify any other types of addresses; therefore, you need to make sure that you specify any custom addresses using the correct syntax. If you're entering an SMTP address, you can include the wildcard character (*) in the address space as defined in RFC 1035. For example, *, *.com, and * are permitted, but * isn't permitted.

      Include all subdomains   This option is only available when you're specifying an SMTP address space. Select this option if you also want to use this connector to route mail to all subdomains of the specified address space. If you entered an address space that contains the wildcard character, this option is automatically selected.

      Cost Use the address space cost to set the selection priority when more than one Send connector is configured for the same address space. During routing resolution, when the connector selection is made, the least cost routing path to the destination address space is selected. The valid input range is from 1 through 100.

    • Edit To modify an existing address space in the address space list, select the address space, and then click Edit. You can configure the same options described for the Add button previously, with the exception of Type. You can't change the type of an existing address space.

    • Remove To delete the domain name from the list of domains, select a domain name, and then click Remove icon.

    • Scoped send connector   By default, all Send connectors that you create can be used by all the Hub Transport servers in your Exchange organization. However, you can limit the scope of any Send connector so that it can be used only by other Hub Transport servers that exist in the same Active Directory site. To limit the scope of this Send connector, select Scoped send connector.

  5. Use the Network tab to configure how outbound mail is routed through the Send connector:

    • Use domain name system (DNS) "MX" records to route mail automatically   Select this option to use DNS to route outbound mail. The connector uses DNS to resolve the IP address of the remote SMTP server.

    • Enable Domain Security (Mutual Auth TLS)   Select this check box to configure this Send connector to attempt to establish a mutual Transport Layer Security (TLS) connection with remote servers when sending mail. There are additional configuration steps required before you can start using TLS. For more information about how to configure mutual TLS, see Using Domain Security: Configuring Mutual TLS.

    • Route mail through the following smart hosts   Select this option to route all outbound mail to specific smart hosts instead of using DNS to resolve the IP addresses of remote SMTP servers.

    • Add   To add a new smart host, click Add. You can specify either of the following options in the window that appears:

      IP Address   Select this option to identify the smart host by IP address (for example:

      Fully qualified domain name (FQDN)   Select this option to identify the smart host by FQDN (for example,

    • Edit   To edit an existing smart host, select the smart host, and then click Edit.

    • Remove   To remove an existing smart host, select the smart host, and then click Remove icon.

    • Smart host authentication   This field shows the authentication type that the connector uses to authenticate with the smart hosts.

      By default, no authentication is used. To configure the smart host authentication settings, click Change. You can specify one of the following options in the window that appears:

      None   Select this option if the smart host is configured to accept anonymous connections.

      Basic Authentication   Select this option if the smart host requires Basic authentication. Basic authentication requires that you provide a user name and password. We strongly recommend that you use an encrypted connection if you're using Basic authentication, because the user name and password are sent in clear text. Select the Basic Authentication over TLS check box to enable encryption on the connection. Also, if you specify more than one smart host for this Send connector, all of the specified smart hosts must accept the same user name and password.

      Exchange Server Authentication   Select this option to authenticate to a smart host by using an Exchange authentication mechanism, such as TLS direct trust or TLS\Kerberos.

      Externally Secured (for example, with IPsec) Select this option if the connection to the smart host is secured by external means, such as being physically secured over a private network or secured using Internet Protocol security (IPsec). When you select this option, you make an assertion of external security that can't be programmatically verified by Exchange.

    • Use the External DNS Lookup settings on the transport server   Select this option to use the external DNS servers list to resolve the names of the remote SMTP servers.


      Verify that you have configured the external DNS servers list by using the Set-TransportServer cmdlet or by using the External DNS Lookups tab in the properties of the Hub Transport server object, or the Edge Transport server object.

  6. Use the Source Server tab to specify the transport servers that can use this Send connector. The list of source servers can contain only Hub Transport servers or only subscribed Edge Transport servers, but not a mix of both. Only those Hub Transport servers in the list use this Send connector for outbound messages. In the case of subscribed Edge Transport servers, the EdgeSync service propagates this Send connector configuration to only the Edge Transport servers in the list.


    The Source Server tab is only available on Hub Transport servers.

    Select one of the following:

    • Add   Click to add a Hub Transport server or a subscribed Edge Transport server.

    • Remove   To remove a server from the list, select the server, and then click Remove icon.


      Removing a subscribed Edge Transport server from the list doesn't remove the Send connector from the Edge Transport server. It just stops the EdgeSync service from propagating this Send connector configuration to that Edge Transport server.

Use the Shell to configure the properties of a Send connector

You need to be assigned permissions before you can perform this procedure. To see what permissions you need, see the "Send connectors" entry in the Transport Permissions topic.

You can use the Set-SendConnector cmdlet to modify all available settings for an existing Send connector. The following command is an example of how you can use this cmdlet to update the properties of a Send connector. In this example, the following changes are made to the configuration of a Send connector named "Connection to":

  • Changes the maximum message size allowed on the connector to 50 MB.

  • Enables protocol logging on the Send connector.

Set-SendConnector "Connection to" -MaxMessageSize 50MB -ProtocolLoggingLevel Verbose

The values that you specify by using the Set-SendConnector cmdlet parameters replace the existing values configured on the Send connector. This isn't an issue for single value attributes such as maximum message size, but it can be a problem for multivalued attributes such as smart hosts or address spaces. To preserve any existing values in a multivalued attribute, you must specify the existing value and any new values that you want to add when you run the Set-SendConnector cmdlet.

For example, assume that you want to add an address space to the "Connection to" Send connector. Currently, this Send connector has a single address space defined,, with a cost of 1. You want to add an address space for with a cost of 10. The following command accomplishes this by specifying the existing value along with the new value being added.

Set-SendConnector "Connection to" -AddressSpaces ";1",";10"

If you have numerous values for a multivalued property, you may not want to retype all of the values just to add another value. To avoid that, you can make use of temporary Shell variables. The following example also adds the address space with a cost of 10 to the "Connection to" Send connector using a temporary variable called $ConnectorConfiguration.

$ConnectorConfiguration = Get-SendConnector "Connection to"
$ConnectorConfiguration.AddressSpaces += ";10"
Set-SendConnector "Connection to" -AddressSpaces $ConnectorConfiguration.AddressSpaces

For detailed syntax and configuration information, see Set-SendConnector.

 © 2010 Microsoft Corporation. All rights reserved.