Colin Walters <walters@cis.ohio-state.edu> writes:

> Hello,
> 
> On "GNU Emacs 21.0.91.1 (i686-pc-linux-gnu, X toolkit)
>  of Sun 2000-11-19 on meta"
> 
> when sending mail, message.el generates the headers here on line 2515:
> 
> 	;; Insert some headers.
> 	(message-generate-headers message-required-news-headers)
> 
> where the Message-ID, Lines, Date, etc are generated.  Then,
> message.el generates these headers again on line 2538:
> 
> 		;; We (re)generate the Lines header.
> 		(when (memq 'Lines message-required-mail-headers)
> 		  (message-generate-headers '(Lines)))
> 
> The comment by the second generation seems to say that only the Lines
> header will be regenerated; in fact, all headers with the
> 'message-deletable text property are deleted, including the
> Message-ID, but are not restored, because only the '(Lines) header is
> passed as a header to generate the second time.
> 
> The following gross hack cures the symptoms, but I think message.el
> should be fixed to not require the headers to be generated twice.

Thank you for the analysis. Try this patch.

ShengHuo