Determines local interface address that is listening.

A String value.  

object.BindIP [= value]

The BindIP Property syntax has these parts:

If you don't want your Smtp server to be publicly accessible (during testing or implementation, for instance) you can make it use only one of your networks interfaces. For instance, if you have local network on IP address 192.168.1.1, and one interface is connected to internet with IP 100.101.102.103, you can make only user's from your local network access Smtp server by setting

wodSmtpServer1.BindIP = "192.168.1.1"

As a result, connections from Internet will be denied (by your OS, not application) and furthermore you will be allowed to run some other Smtp server on same port - on different interface.
 

If you want your server to be accessible only from your computer, set it up like this:

wodSmtpServer1.BindIP = "127.0.0.1"

To make Smtp server bind to all interfaces, just leave this property empty.