(Unwanted) case sensitivity in nnmail-process-unix-mail-format

[Steven L Baur <steve@miranova.com>]

nnmail-process-unix-mail-format explicitly sets case-fold-search to
nil.  This causes the test for a previous message to lose when it does
not match Message-ID: exactly.  Since all headers are case
insensitive, either the tests:

	(if (re-search-forward "^Message-ID:[ \t]*\\(<[^>]+>\\)" nil t)
	    (setq message-id (match-string 1))
	  (save-excursion
	    (when (re-search-forward "^Message-ID:" nil t)
	      (beginning-of-line)
	      (insert "Original-")))
	  ;; There is no Message-ID here, so we create one.
	  (forward-line 1)
	  (insert "Message-ID: " (setq message-id (nnmail-message-id)) "\n"))

are incorrect, or the binding of case-fold-search to nil is incorrect.

There are a number of mailers that will attach a message id as
Message-Id: so this definitely needs fixing.
-- 
steve@miranova.com baur
Unsolicited commercial e-mail will be billed at $250/message.
What are the last two letters of "doesn't" and "can't"?
Coincidence?  I think not.