The .NET SmtpClient (System.Net.Mail.SmtpClient) is obsolete most importantly because it does NOT support asynchronous operations. However, the SmtpClient alone will not allow you to send emails, you will still need to connect to an smtp server and while Gmail SMTP is perfect for development, it cannot be used for production - hence the longer tutorial.
In addition I often find telnet useful for testing email infrastructure and wanted to add that to the tutorial/documentation.
Even so, I do realize that the tutorial is
echatramdom spin quite long.
