Setting up Outbound Relay (SMTP Connector) - Exchange 2010 & 2013

Exchange 2013

  1. In the EAC, navigate to Mail flow > Send connectors, and then click Add .
  2. In the New send connector wizard, specify a name for the send connector and then select Internet for the Type. Click Next.
  3. Select Route mail through smart hosts. Click the plus sign and add the FQDN target using the format <> (example:  Save and Click Next.
  4. Under Address space, click Add. In the Add domain window, make sure SMTP is listed as the Type. For Fully Qualified Domain Name (FQDN), enter *, which indicates that this send connector applies to messages addressed to any domain. Leave the *Cost set at 1 and the *Type set at SMTP.  Click Save.
  5. Make sure Scoped send connector is not selected and then click Next.
  6. For Source server, click Add. In the Select a server window, select a Mailbox server that will be used to send mail to the Internet via the Client Access server and click Add . After you've selected the server, click Add . Click OK.
  7. Click Finish.

Once you have created the Send connector, it appears in the Send connector list.

In Exchange 2013 you can use the FrontendProxyEnabled parameter of the Set-SendConnector cmdlet to route outbound messages through the Client Access server. This parameter is not set to $true by default, but in many cases it can consolidate and simplify mail flow, especially if you are working with an environment with a large number of messaging servers.

This example sets the FrontendProxyEnabled parameter to $true on a Send connector.

Set-SendConnector " Send Connector" -FrontendProxyEnabled $true


 See attached document (bottom of the page) for screenshots and examples.


Exchange 2010

    1. Open the Exchange Management Console (EMC)
    2. Navigate to Organization Configuration, and click on Hub Transport
    3. In the right hand pane, select Send Connectors
    4. Next, select New Send Connector under the Actions pane
    5. Complete the Name field
    6. Select Custom, and then click Next
    7. Select Add New Address Space.  For Address, enter *, which indicates that this send connector applies to messages addressed to any domain. Leave the Cost set at 1 and the Type set at SMTP.  Click Save.  

    8. Click OK and select Next
    9. Under Network Settings, select Route mail through the following smart host, and click Add
    10. Select Fully qualified domain name, and enter  (where domain is the name of your authoritative domain), then click OK: Example FQDN -

    11. For the Authentication Settings, select the default None
    12. Add the Source Server/s and click Next:
    13. The next screen shows summary details of the connector.  Confirm that everything is correct, and click Next. This will start a test of the connector
    14. Click Finish.
  1. Using shell to create 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.

This command creates a Send connector.  

New-SendConnector -Name <Connector Name> -AddressSpaces <Address Space> <Optional Parameters>

This example creates a Send connector called Subsidiary Send Connector that has the following settings:

  • Connector usage type is Custom.
  • Connector sends messages to the SMTP address space and all subdomains. The address space cost is 5.
  • Connector sends messages to the SMTP address space named and all subdomains. The address space cost is 8.
  • E-mail is routed through a smart host at IP address
  • Maximum message size of 50 MB is allowed on this connector. 
New-SendConnector -Name "Subsidiary Send Connector" -Usage Custom -AddressSpace "*;5","*;8" -DNSRoutingEnabled $false -SmartHosts -MaxMessageSize 50MB

For detailed syntax and parameter information, see New-SendConnector.

Legacy - Exchange 2003

To create and securely configure the SMTP connector follow these steps:

  1. Start Exchange System Manager.

    Note After you install Exchange Server in an Exchange 2003 organization, Exchange System Manager does not automatically display routing groups and administrative groups. You must configure the Exchange organization to display routing groups and administrative groups. 

  2. Expand the Administrative Groups container. To do so, click the plus sign (+) to the left of the container.
  3. Click the administrative group that you want to work with, and then expand it.
  4. Expand the Routing Groups container.
  5. Click the routing group that you want to work with, and then expand it.
  6. Click the Connectors container. Right-click the Connectors container, and then click New.
  7. Click SMTP Connector.
  8. On the General tab, provide an appropriate identifying name for the connector.
  9. Choose to use DNS forwarding to a FQDN of yourdomain.outbound.emailservice.op.  Example:
  10. Under Local Bridgeheads, click Add. Add the server that becomes the bridgehead server for the routing group. Designate an SMTP virtual server as a bridgehead server for the SMTP connector. This can be either the server that you are working on or another server in the same routing group. Alternatively, this duty can be shared by multiple servers.
  11. Click the Address Space tab. Under Connector Scope, click either Entire Organization or Routing Group. As in earlier versions of Exchange Server, when you configure the Internet Mail Service, click Add, click SMTP, and then click OK. Accept the default (*) unless you require outbound e-mail domain restriction, and leave the cost as 1. If you have accepted the default of (*), you should never click to select the Allow messages to be relayed to these domains check box. Clicking to select the Allow messages to be relayed to these domains check box would open your server for relay to the world. The Allow messages to be relayed to these domains check box should be for secure domain to domain connections only.
  12. If you have chosen forward all mail to a smart host, click the Advanced tab. Click the Outbound Security option, and then select an appropriate authentication method for your relay host. The default is Anonymous Access. 
  13. Click OK to exit Outbound Security.
  14. Click OK to exit the Advanced tab.
  15. Click OK to exit the SMTP connector.
  16. You must restart the Microsoft Exchange Routing Engine service and the SMTP service for these changes to take effect.
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