I've recently moved over to Windows Vista Business and noticed that there is no SMTP server. So if you're developing any type of web application that sends email you've got a problem if you are wanting to use your localhost as the smtp server.
I've found this application which is free mini-relay (The site is in Spanish, but the app is English, scroll to the bottom of the page and download).
Its even got the option to startup when you login to Windows and run on the system tray.
