Cer-tech .com has a Windows Server 2008 server named S1. You have installed Web Server （IIS） serverrole on S1. The server has an SMTP gateway that connects to the internet. You have an internal firewallinstalled on the network which prevents all client machines from establishing a connection to the internetexcept the SMTP gateway over TCP port 25.You configure the SMTP gateway to relay e-mail for S1. What should you do to configure a website on S1 to send email to internet users？（）

• A、Install and configure SMTP server feature on S1
• B、Configure the SMTP email feature for the website on S1
• C、Create a DNS server on S1 and configure the SMTP mail service
• D、Create an MX record for the SMTP gateway on an internal DNS server
• E、None of the above