How Can I Test Sending Emails using localhost?

Seems like i need to not use the ASP.Net Development Server and switch over to IIS

Easy enough:

WEB Project Properties -> Web -> Use Local IIS Web Server

However, when i then go to debug i get:

Unable to start debugging on the server. Debugging failed because integrated windows authentication is not enabled...

So I go into IIS and change the Site to use Integrated Windows Authentication ... but then i get the site prompting me for a password when i either browse to it via IIS or if i start debugging.