Working with System.Web.Mail namespace...
We use System.Web.Mail namespace to send emails from our .NET Applications. It uses two main classes called MailMessage and SmtpServer. The latter having a single static property to indicate the email server (smtp host) to use and a public method taking an instance of MailMessage carrying the mail to be delivered.
Internally it is supposed to be a wrapper on the CDO Object and lot of P/Invoke stuff being builtin, the exception stack too can be significantly larger. Quite interestingly, there is one website called http://www.systemwebmail.com/ which I would like to share with the readers which discusses at length, System.Web.Mail namespace, FAQ etc.