[ This article is posted at ElMajdal.Net website : http://elmajdal.net/ExchangeServer/How_To_Create_A_Send_Connector_In_Exchange_Server_2010.aspx ]
Exchange 2010 transport servers require Send Connectors to deliver messages to the next hop on the way to their destination
The Send Connector is created only on the Hub Transport or Edge Server role. Send connectors that are created on Hub Transport servers are stored in Active Directory and are available to all Hub Transport servers in the organization. If a Send connector is configured to send messages to an external domain, any Hub Transport server in the organization will route a message for that domain to a source server for that connector to be relayed to the destination domain. I have a typical Exchange Server installation, that consist of the Client Access, Hub Transport, and Mailbox server roles, along with the Exchange Management Console on a single server. So I will be creating the Send Connector on the Hub Transport.
Open Exchange Server Management Console and Expand the Organization Configuration node from the left side pane
Click on Hub Transport, and then click on the Send Connectors Tab As you can see, by default there is no Send Connectors available.
To create a new Send Connector, you will need either to : Right click on Hub Transport and select New Send Connector... Or under the Send Connectors Tab, right click any empty area and select New Send Connector... Or from the right side pane, under Actions, click on New Send Connector...
Custom : Select this option to create a customized connector to connect with systems that aren't servers running Exchange 2010.
Internal : Internal Send connectors send e-mail to servers in your Exchange organization. This connector is configured to route e-mail to your internal Exchange servers as smart hosts.
Internet : Internet Send connectors send e-mail to the Internet. This connector is configured to use Domain Name System (DNS) MX records to route e-mail.
Partner : Partner Send connectors send e-mail to partner domains. This connector is configured to only allow connections to servers that authenticate with Transport Layer Security (TLS) certificates for SMTP domains included in the list of domain-secured domains. You can add domains to this list by using the TLSSendDomainSecureList parameter in the Set-TransportConfig command. I will be creating an Internet Send Connector, so I will select the type as Internet
Now open Outlook Web App (OWA) and try to send an email to an external domain, you will find out that the email will be sent successfully.