Creating a Custom Receive Connector in Exchange 2013

Receive Connectors are used to control the flow of inbound messages into Exchange. With Exchange 2013 they are configured on servers with the Transport service (all mailbox servers) or with the Front End Transport service (all Client Access servers).

This means we can configure a Receive Connector in two different places... However, the big difference is that the Front End Transport service does not queue any messages locally while the Transport service does! Therefore, if you want Exchange to queue e-mails received by a custom Receive Connector (for example, in case of a problem with the recipient’s mailbox) you have to create it on your Mailbox servers.

Obviously, all the Receive Connectors required for internal mail flow are automatically created when a Client Access server or Mailbox server is installed. While Exchange 2007/2010 Hub Transport servers were not configured out of the box to accept e-mails from the internet, the new Client Access server comes with a Receive Connector named “Default Frontend server_name” already configured to allow “Anonymous Users” to connect to it to allow inbound flow from the Internet.

But sometimes custom Receive Connectors are required for various reasons: to control which servers receive messages from a particular IP address; to configure special connector properties for messages received from a particular IP address such as allowing larger messages or more recipients per messages; or to allow servers, applications or devices such as printers to establish unauthenticated SMTP connections to Exchange in order to send e-mails.

To create Receive Connectors in Exchange 2013 we can use the Exchange Administration Center [EAC] or the Exchange Management Shell [EMS]. In this tip, we will be using the Shell to create a Receive Connector that:
• Is associated with the Mailbox server called MBX1;
• Listens for incoming SMTP connections on the IP address 10.10.1.1 and port 25;
• Accepts incoming SMTP connections only from the IP range of 192.168.1.1 to 192.168.1.10;
• Accepts e-mails of a size up to 50MB;

New-ReceiveConnector -Name “Application 1” –Server MBX1 -Usage Custom -Bindings 10.10.1.1:25 -RemoteIPRanges 192.168.1.1-192.168.1.10 -MaxMessageSize 50MB

But what if a server is multi-role and has the Client Access and Mailbox server roles? How does Exchange know which role to associate the Receive Connector with? For these situations we have the TransportRole parameter exactly to designate the server role associated with this connector. The valid types are FrontendTransport and HubTransport.

So our example would become:

New-ReceiveConnector -Name “Application 1” –Server MBX1 -Usage Custom -Bindings 10.10.1.1:25 -RemoteIPRanges 192.168.1.1-192.168.1.10 -MaxMessageSize 50MB –TransportRole HubTransport