There are times when developing that I want to be able to see what the contents will be for emails generated from my application, but I do not want the emails to actually go to the reciepients.  In addition I may not have my local development machine set up to relay mail.

Sometime, updating the development system email addresses to a generic address makes sense.  Other times, I do not or cannot do this, so instead, I opt for the following technique.

With this approach, you add a configuration setting to your config file, and the result is that the email will be placed in a directory of your choosing, but will not actually be sent.

To accomplish this, add the below setting to your config file:

 <system.net>
    <mailSettings>
      <smtp deliveryMethod='SpecifiedPickupDirectory'>
        <specifiedPickupDirectory pickupDirectoryLocation="C:\All\Maildrop" />
      </smtp>
    </mailSettings>    
  </system.net>

 Now, when you send your email using code similar to below, the email will appear in the directory you specified.

 MailMessage message = new MailMessage();
 message.From = new MailAddress(...

... other code to set to, body goes here

SmtpClient smtpClient = new SmtpClient();
smtpClient.Send(message);