This chapter has touched on the most widely used networking types,
but for completeness we should mention that some more specialized
networking APIs are available. For example, the System.Net.Mail
namespace provides types for
sending email through an SMTP relay, and the related System.Net.Mime
namespace supports MIME features, which are the standard way to represent
attachments for emails. The System.Net.PeerToPeer
namespaces provide access
to the peer-to-peer networking features of Windows. (There are also
WCF bindings that support this system.) The System.Net.NetworkInformation
namespace provides
types for discovering network status, through network interface
information, and TCP/IP ICMP mechanisms such as ping. The TLS/SSL infrastructure that enables HTTPS to send
encrypted data is also available for you to use directly, through the
System.Net.Security
namespace.