Here's the code to send an e-mail using .Net 2.0's System.Net.Mail namespace. Your SMTP server address is specified in the SmtpClient object's constructor. If you don't know your server address you may be able to find it in your e-mail client's configuration.

Note: the .Net 1.1 System.Web.Mail namespace is obsolete as of .Net 2.0. Use the System.Net.Mail namespace in .NET >= 2.0 apps.

using (MailMessage mailMessage = new MailMessage(new MailAddress(fromTextBox.Text), 
                                                 new MailAddress(toTextBox.Text)))
{
  mailMessage.Body    = bodyTextBox.Text;
  mailMessage.Subject = subjectTextBox.Text;

  try
  {
    SmtpClient smtpClient = new SmtpClient(serverAddressTextBox.Text);
    smtpClient.Send(mailMessage);
  }
  catch (Exception ex)
  {
    MessageBox.Show(ex.Message, "EMail", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
  }
}