MHC is designed to help those who receive most appointments via email.
Using MHC, you can easily import schedule articles from emails.

To use mhc, you must install some of the supported MUA.
The supported MUA are Mew, Wanderlust and Gnus.
Minimum setup:

;;; for Mew user:
(autoload 'mhc-mew-setup "mhc-mew")
(add-hook 'mew-init-hook 'mhc-mew-setup)
;; optional setting for Mew-1.94 (Raw JIS header decoding)
;(add-hook 'mew-message-hook 'mhc-mew-decode-header)
;;; for Wanderlust user:
(autoload 'mhc-wl-setup "mhc-wl")
(add-hook 'wl-init-hook 'mhc-wl-setup)
;;; for Gnus user:
(autoload 'mhc-gnus-setup "mhc-gnus")
(add-hook 'gnus-startup-hook 'mhc-gnus-setup)
;; icon setting for emacs20 (with bitmap-mule) or emacs21
;(setq mhc-icon-path "/usr/local/share/emacs/etc/mhc/icons")

WWW: http://www.quickhack.net/mhc/