Deployment option C: Installing Mail essentials on Exchange 2000 - multiple IP mode (Inbound & Outbound security) Note: Use this deployment option only if you are confident with IIS 5 configuration. We recommend you install Mail essentials on a separate machine if at all possible. This deployment option is a little more complex to configure. Basically it requires a second IP and also creating a second virtual server on the Exchange machine. Use this option if its not possible for you to use a separate machine and you must content check outbound mail. Go to the paragraph 'Installing Mail essentials on Exchange 2000 – multiple IP mode' for instructions how to install this deployment option.