Configuring a Dual-Homed Server Using the Wizard
When you use Internet Mail Wizard to configure Internet mail delivery on a dual-homed server (a server configured with two or more network addresses, typically with two network interface cards), the wizard performs the required configuration steps.
The wizard also creates an additional SMTP virtual server on the Exchange server. It configures Internet mail delivery in the following ways:
To configure a server to send Internet mail, the wizard guides you through the process of assigning the intranet IP address to the default SMTP virtual server on which it creates the SMTP connector to send outbound mail. You assign the intranet IP address to this virtual server so that only internal users on your intranet can send outbound mail.
To configure a server to receive Internet mail, the wizard guides you through the process of assigning the Internet IP address to the Internet SMTP virtual server. You assign an Internet IP address to this virtual server because external servers must be able to connect to this SMTP virtual server to send Internet mail. Additionally, you must have an MX record on your DNS server that references this server and the IP address of the Internet SMTP virtual server.
Important
To increase the security on a dual-homed server, use Internet Protocol security (IPSec) policies to filter ports on the Internet network interface card and strictly limit the users who you permit to log on to this server. For more information about IPSec, see your Windows documentation.