Test Emails in ASP.NET without a Mail Server

The tip I am going to share today is an old one but many developers do not know about it. Assume you are creating an application and need to test a module that sends out bulk mails, like a newsletter. Your first thought would be to configure an SMTP server to test the email module. However there is a trick that you can make use of while testing your code. Use the following setting in your web.config