Exchange 2013 servers running the Transport service require Receive connectors to receive messages from the Internet, from email clients, and from other email servers. A Receive connector controls inbound connections to the Exchange organization.
Creation of Exchange 2013 receive connector :
In the Exchange Admin Center navigate to Mail Flow -> Receive Connectors. Select the server that you wish to create the receive connector on. Remember, the server should be either a multi-role server or a Client Access server.
Step2 : Click the + icon to create a new receive connector.
Step3 :Give the new connector a name. Exchange names the various default connectors using a standard of “Purpose SERVERNAME”, for example “Client Frontend E15MB1″. So I tend to stick with that convention.
Step4:If the server you chose is multi-role you’ll need to select the Frontend Transport role. If the server is CAS-only then Frontend Transport will already be selected.
Step5 :Leave the Type set to Custom, and then click Next.
Step6 :For servers with a single network adapter the default binding will usually be fine.
Step7:For the remote network settings, click the - icon to remove the default IP address range. Then click the + icon and add at least one IP address of an application server or device that requires external SMTP relay access.
Click Finish to create the new receive connector.
Step 8:Next we need to configure some additional settings for the receive connector. Highlight the connector and click the “pencil” icon to edit its settings. Select Security and tick the Anonymous Users box.
Click Save to apply the settings