From: Richard Stallman <rms@gnu.org>
   Reply-To: rms@gnu.org
   Date: Thu, 10 Oct 2002 04:43:06 -0400

   Would you please fix this bug in metamail.el in the latest Emacs?
   (Are you still maintaining it?)

  >> I looked at that file and I noticed
  >> that the header "Content-Type: MULTIPART/MIXED;" is missing in it. For
  >> some reason emacs removes it before running metamail. 

This is because rmail-ignored-headers includes MIME related headers,
such as "Content-Type:".  Simple user level solution is to put the
following code in .emacs.  It is much better to remove these headers
from rmail-ignored-headers in the next release of emacs distribution.

;; Leave MIME related headers.
(let ((headers '("\\|^mime-version:"
		 "\\|^content-transfer-encoding:"
		 "\\|^content-type:"))
      (case-fold-search t))
  (while headers
    (if (string-match (regexp-quote (car headers)) rmail-ignored-headers)
	(setq rmail-ignored-headers
	      (concat (substring rmail-ignored-headers 0 (match-beginning 0))
		      (substring rmail-ignored-headers (match-end 0)))))
    (setq headers (cdr headers))))