1. Open Server Manager Console and under Features select Add Features
2. Select SMTP Server option
3. Click on Install wait until finish and click close
4. Open IIS 6.0 Manager under Administrative Tools -> Internet Information Services 6.0
5. Under [SMTP Virtual Server] second mouse click and properties
6. Select Relay under Access Tab
7. Select Only the list below and click on Add button
8. Enter IP Address 127.0.0.1 for relay
9. Send a manual email through telnet to confirm everything working successfully. Telnet localhost 25 or telnet yourpublicip 25 and make sure you open the specific port on your firewall to be available to public.