* Gnus: (gnus). The news reader Gnus.
* Message: (message). The Message sending thingamabob.
* Emacs MIME: (emacs-mime). Libraries for handling MIME.
+* Sieve: (sieve). Managing Sieve scripts in Emacs.
+* PGG: (pgg). Emacs interface to various PGP implementations.
+* auth-source: (auth). Emacs interface to keeping login information.
+* SASL: (sasl). The Emacs SASL library.