Automatically start SMTP server in IIS?
Open the run dialog on the server, and enter services.msc. Locate the 'Simple Mail Transfer Protocol (SMTP)' service, right click, choose Properties and set the service to Automatic. From now on, it will start at boot
The display name in the services list is "Simple Mail Transfer Protocol (SMTP)"
Set the Startup Type to Automatic
You may also want to select the Recovery tab and set the service to restart on failures.