How to Test a .NET Application That Uses SMTP

How many times you had to set up a SMTP service just to test that your .NET application sends the e-mail correctly? I found that I can test the actual application (not the SMTP delivery) by using a bogus SMTP server in the config file.

It pretends to be a SMTP server but it "delivers" the messages by leaving them into a folder you specify.

<system.net>  
  <mailSettings>  
    <smtp from="**admin@domain.com**" deliveryMethod="SpecifiedPickupDirectory">  
      <specifiedPickupDirectory pickupDirectoryLocation="**c:MailFolder**"/>  
    </smtp>  
  </mailSettings>  
</system.net>