(message-idna-inside-rhs-p): Removed.

[gnus] / texi / message.texi

\input texinfo                  @c -*-texinfo-*-

@setfilename message
@settitle Message Manual
@synindex fn cp
@synindex vr cp
@synindex pg cp
@dircategory Emacs
@direntry
* Message: (message).   Mail and news composition mode that goes with Gnus.
@end direntry
@iftex
@finalout
@end iftex
@setchapternewpage odd

@ifnottex

This file documents Message, the Emacs message composition mode.

Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 
Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.1 or
any later version published by the Free Software Foundation; with no
Invariant Sections, with the Front-Cover texts being ``A GNU
Manual'', and with the Back-Cover Texts as in (a) below.  A copy of the
license is included in the section entitled ``GNU Free Documentation
License'' in the Emacs manual.

(a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify
this GNU Manual, like GNU software.  Copies published by the Free
Software Foundation raise funds for GNU development.''

This document is part of a collection distributed under the GNU Free
Documentation License.  If you want to distribute this document
separately from the collection, you can do so by adding a copy of the
license to the document, as described in section 6 of the license.
@end ifnottex

@tex

@titlepage
@title Message Manual

@author by Lars Magne Ingebrigtsen
@page

@vskip 0pt plus 1filll
Copyright @copyright{} 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003
     Free Software Foundation, Inc.

Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.1 or
any later version published by the Free Software Foundation; with the
Invariant Sections being none, with the Front-Cover texts being ``A GNU
Manual'', and with the Back-Cover Texts as in (a) below.  A copy of the
license is included in the section entitled ``GNU Free Documentation
License'' in the Emacs manual.

(a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify
this GNU Manual, like GNU software.  Copies published by the Free
Software Foundation raise funds for GNU development.''

This document is part of a collection distributed under the GNU Free
Documentation License.  If you want to distribute this document
separately from the collection, you can do so by adding a copy of the
license to the document, as described in section 6 of the license.
@end titlepage
@page

@end tex

@node Top
@top Message

All message composition from Gnus (both mail and news) takes place in
Message mode buffers.

@menu
* Interface::         Setting up message buffers.
* Commands::          Commands you can execute in message mode buffers.
* Variables::         Customizing the message buffers.
* Compatibility::     Making Message backwards compatible.
* Appendices::        More technical things.
* Index::             Variable, function and concept index.
* Key Index::         List of Message mode keys.
@end menu

This manual corresponds to Message v5.10.6.  Message is distributed
with the Gnus distribution bearing the same version number as this
manual.


@node Interface
@chapter Interface

When a program (or a person) wants to respond to a message---reply,
follow up, forward, cancel---the program (or person) should just put
point in the buffer where the message is and call the required command.
@code{Message} will then pop up a new @code{message} mode buffer with
appropriate headers filled out, and the user can edit the message before
sending it.

@menu
* New Mail Message::     Editing a brand new mail message.
* New News Message::     Editing a brand new news message.
* Reply::                Replying via mail.
* Wide Reply::           Responding to all people via mail.
* Followup::             Following up via news.
* Canceling News::       Canceling a news article.
* Superseding::          Superseding a message.
* Forwarding::           Forwarding a message via news or mail.
* Resending::            Resending a mail message.
* Bouncing::             Bouncing a mail message.
* Mailing Lists::        Send mail to mailing lists.
@end menu


@node New Mail Message
@section New Mail Message

@findex message-mail
The @code{message-mail} command pops up a new message buffer.

Two optional parameters are accepted: The first will be used as the
@code{To} header and the second as the @code{Subject} header.  If these
are @code{nil}, those two headers will be empty.


@node New News Message
@section New News Message

@findex message-news
The @code{message-news} command pops up a new message buffer.

This function accepts two optional parameters.  The first will be used
as the @code{Newsgroups} header and the second as the @code{Subject}
header.  If these are @code{nil}, those two headers will be empty.


@node Reply
@section Reply

@findex message-reply
The @code{message-reply} function pops up a message buffer that's a
reply to the message in the current buffer.

@vindex message-reply-to-function
Message uses the normal methods to determine where replies are to go
(@pxref{Responses}), but you can change the behavior to suit your needs
by fiddling with the @code{message-reply-to-function} variable.

If you want the replies to go to the @code{Sender} instead of the
@code{From}, you could do something like this:

@lisp
(setq message-reply-to-function
      (lambda ()
       (cond ((equal (mail-fetch-field "from") "somebody")
               (list (cons 'To (mail-fetch-field "sender"))))
             (t
              nil))))
@end lisp

This function will be called narrowed to the head of the article that is
being replied to.

As you can see, this function should return a string if it has an
opinion as to what the To header should be.  If it does not, it should
just return @code{nil}, and the normal methods for determining the To
header will be used.

This function can also return a list.  In that case, each list element
should be a cons, where the @sc{car} should be the name of a header
(e.g. @code{Cc}) and the @sc{cdr} should be the header value
(e.g. @samp{larsi@@ifi.uio.no}).  All these headers will be inserted into
the head of the outgoing mail.


@node Wide Reply
@section Wide Reply

@findex message-wide-reply
The @code{message-wide-reply} pops up a message buffer that's a wide
reply to the message in the current buffer.  A @dfn{wide reply} is a
reply that goes out to all people listed in the @code{To}, @code{From}
(or @code{Reply-to}) and @code{Cc} headers.

@vindex message-wide-reply-to-function
Message uses the normal methods to determine where wide replies are to go,
but you can change the behavior to suit your needs by fiddling with the
@code{message-wide-reply-to-function}.  It is used in the same way as
@code{message-reply-to-function} (@pxref{Reply}).

@vindex message-dont-reply-to-names
Addresses that match the @code{message-dont-reply-to-names} regular
expression will be removed from the @code{Cc} header.

@vindex message-wide-reply-confirm-recipients
If @code{message-wide-reply-confirm-recipients} is non-@code{nil} you
will be asked to confirm that you want to reply to multiple
recipients.  The default is @code{nil}.

@node Followup
@section Followup

@findex message-followup
The @code{message-followup} command pops up a message buffer that's a
followup to the message in the current buffer.

@vindex message-followup-to-function
Message uses the normal methods to determine where followups are to go,
but you can change the behavior to suit your needs by fiddling with the
@code{message-followup-to-function}.  It is used in the same way as
@code{message-reply-to-function} (@pxref{Reply}).

@vindex message-use-followup-to
The @code{message-use-followup-to} variable says what to do about
@code{Followup-To} headers.  If it is @code{use}, always use the value.
If it is @code{ask} (which is the default), ask whether to use the
value.  If it is @code{t}, use the value unless it is @samp{poster}.  If
it is @code{nil}, don't use the value.


@node Canceling News
@section Canceling News

@findex message-cancel-news
The @code{message-cancel-news} command cancels the article in the
current buffer.

@vindex message-cancel-message
The value of @code{message-cancel-message} is inserted in the body of
the cancel message.  The default is @samp{I am canceling my own
article.}.

@cindex Cancel Locks
@vindex message-insert-canlock
@cindex canlock
When Message posts news messages, it inserts @code{Cancel-Lock}
headers by default.  This is a cryptographic header that ensures that
only you can cancel your own messages, which is nice.  The downside
is that if you lose your @file{.emacs} file (which is where Gnus
stores the secret cancel lock password (which is generated
automatically the first time you use this feature)), you won't be
able to cancel your message.

Whether to insert the header or not is controlled by the
@code{message-insert-canlock} variable.

Not many news servers respect the @code{Cancel-Lock} header yet, but
this is expected to change in the future.


@node Superseding
@section Superseding

@findex message-supersede
The @code{message-supersede} command pops up a message buffer that will
supersede the message in the current buffer.

@vindex message-ignored-supersedes-headers
Headers matching the @code{message-ignored-supersedes-headers} are
removed before popping up the new message buffer.  The default is@*
@samp{^Path:\\|^Date\\|^NNTP-Posting-Host:\\|^Xref:\\|^Lines:\\|@*
^Received:\\|^X-From-Line:\\|Return-Path:\\|^Supersedes:}.



@node Forwarding
@section Forwarding

@findex message-forward
The @code{message-forward} command pops up a message buffer to forward
the message in the current buffer.  If given a prefix, forward using
news.

@table @code
@item message-forward-ignored-headers
@vindex message-forward-ignored-headers
All headers that match this regexp will be deleted when forwarding a message.

@item message-make-forward-subject-function
@vindex message-make-forward-subject-function
A list of functions that are called to generate a subject header for
forwarded messages.  The subject generated by the previous function is
passed into each successive function.

The provided functions are:

@table @code
@item message-forward-subject-author-subject
@findex message-forward-subject-author-subject
Source of article (author or newsgroup), in brackets followed by the
subject.

@item message-forward-subject-fwd
Subject of article with @samp{Fwd:} prepended to it.
@end table

@item message-wash-forwarded-subjects
@vindex message-wash-forwarded-subjects
If this variable is @code{t}, the subjects of forwarded messages have
the evidence of previous forwards (such as @samp{Fwd:}, @samp{Re:},
@samp{(fwd)}) removed before the new subject is
constructed.  The default value is @code{nil}.

@item message-forward-as-mime
@vindex message-forward-as-mime
If this variable is @code{t} (the default), forwarded messages are
included as inline @acronym{MIME} RFC822 parts.  If it's @code{nil}, forwarded
messages will just be copied inline to the new message, like previous,
non @acronym{MIME}-savvy versions of Gnus would do.

@item message-forward-before-signature
@vindex message-forward-before-signature
If non-@code{nil}, put forwarded message before signature, else after.

@end table


@node Resending
@section Resending

@findex message-resend
The @code{message-resend} command will prompt the user for an address
and resend the message in the current buffer to that address.

@vindex message-ignored-resent-headers
Headers that match the @code{message-ignored-resent-headers} regexp will
be removed before sending the message.  The default is
@samp{^Return-receipt}.


@node Bouncing
@section Bouncing

@findex message-bounce
The @code{message-bounce} command will, if the current buffer contains a
bounced mail message, pop up a message buffer stripped of the bounce
information.  A @dfn{bounced message} is typically a mail you've sent
out that has been returned by some @code{mailer-daemon} as
undeliverable.

@vindex message-ignored-bounced-headers
Headers that match the @code{message-ignored-bounced-headers} regexp
will be removed before popping up the buffer.  The default is
@samp{^\\(Received\\|Return-Path\\):}.


@node Mailing Lists
@section Mailing Lists

@cindex Mail-Followup-To
Sometimes while posting to mailing lists, the poster needs to direct
followups to the post to specific places.  The Mail-Followup-To (MFT)
was created to enable just this.  Two example scenarios where this is
useful:

@itemize @bullet
@item
A mailing list poster can use MFT to express that responses should be
sent to just the list, and not the poster as well.  This will happen
if the poster is already subscribed to the list.

@item
A mailing list poster can use MFT to express that responses should be
sent to the list and the poster as well.  This will happen if the poster
is not subscribed to the list.

@item
If a message is posted to several mailing lists, MFT may also be used
to direct the following discussion to one list only, because
discussions that are spread over several lists tend to be fragmented
and very difficult to follow.

@end itemize

Gnus honors the MFT header in other's messages (i.e. while following
up to someone else's post) and also provides support for generating
sensible MFT headers for outgoing messages as well.

@c @menu
@c * Honoring an MFT post::        What to do when one already exists
@c * Composing with a MFT header:: Creating one from scratch.
@c @end menu

@c @node Composing with a MFT header
@subsection  Composing a correct MFT header automagically

The first step in getting Gnus to automagically generate a MFT header
in posts you make is to give Gnus a list of the mailing lists
addresses you are subscribed to.  You can do this in more than one
way.  The following variables would come in handy.

@table @code

@vindex message-subscribed-addresses
@item message-subscribed-addresses
This should be a list of addresses the user is subscribed to.  Its
default value is @code{nil}.  Example:
@lisp
(setq message-subscribed-addresses
      '("ding@@gnus.org" "bing@@noose.org"))
@end lisp

@vindex message-subscribed-regexps
@item message-subscribed-regexps
This should be a list of regexps denoting the addresses of mailing
lists subscribed to.  Default value is @code{nil}.  Example: If you
want to achieve the same result as above:
@lisp
(setq message-subscribed-regexps
      '("\\(ding@@gnus\\)\\|\\(bing@@noose\\)\\.org")
@end lisp

@vindex message-subscribed-address-functions
@item message-subscribed-address-functions
This can be a list of functions to be called (one at a time!!) to
determine the value of MFT headers.  It is advisable that these
functions not take any arguments.  Default value is @code{nil}.

There is a pre-defined function in Gnus that is a good candidate for
this variable.  @code{gnus-find-subscribed-addresses} is a function
that returns a list of addresses corresponding to the groups that have
the @code{subscribed} (@pxref{Group Parameters, ,Group Parameters,
gnus, The Gnus Manual}) group parameter set to a non-@code{nil} value.
This is how you would do it.

@lisp
(setq message-subscribed-address-functions
      '(gnus-find-subscribed-addresses))
@end lisp

@vindex message-subscribed-address-file
@item message-subscribed-address-file
You might be one organised human freak and have a list of addresses of
all subscribed mailing lists in a separate file!  Then you can just
set this variable to the name of the file and life would be good.

@end table

You can use one or more of the above variables.  All their values are
``added'' in some way that works :-)

Now you are all set.  Just start composing a message as you normally do.
And just send it; as always.  Just before the message is sent out, Gnus'
MFT generation thingy kicks in and checks if the message already has a
MFT field.  If there is one, it is left alone.  (Except if it's empty -
in that case, the field is removed and is not replaced with an
automatically generated one.  This lets you disable MFT generation on a
per-message basis.)  If there is none, then the list of recipient
addresses (in the To: and Cc: headers) is checked to see if one of them
is a list address you are subscribed to.  If none of them is a list
address, then no MFT is generated; otherwise, a MFT is added to the
other headers and set to the value of all addresses in To: and Cc:

@kindex C-c C-f C-a
@findex message-generate-unsubscribed-mail-followup-to
@kindex C-c C-f C-m
@findex message-goto-mail-followup-to
Hm.  ``So'', you ask, ``what if I send an email to a list I am not
subscribed to?  I want my MFT to say that I want an extra copy.''  (This
is supposed to be interpreted by others the same way as if there were no
MFT, but you can use an explicit MFT to override someone else's
to-address group parameter.)  The function
@code{message-generate-unsubscribed-mail-followup-to} might come in
handy.  It is bound to @kbd{C-c C-f C-a} by default.  In any case, you
can insert a MFT of your own choice; @kbd{C-c C-f C-m}
(@code{message-goto-mail-followup-to}) will help you get started.

@c @node Honoring an MFT post
@subsection Honoring an MFT post

@vindex message-use-mail-followup-to
When you followup to a post on a mailing list, and the post has a MFT
header, Gnus' action will depend on the value of the variable
@code{message-use-mail-followup-to}.  This variable can be one of:

@table @code
@item use
 Always honor MFTs.  The To: and Cc: headers in your followup will be
 derived from the MFT header of the original post.  This is the default.

@item nil
 Always dishonor MFTs (just ignore the darned thing)

@item ask
Gnus will prompt you for an action.

@end table

It is considered good netiquette to honor MFT, as it is assumed the
fellow who posted a message knows where the followups need to go
better than you do.

@node Commands
@chapter Commands

@menu
* Buffer Entry::        Commands after entering a Message buffer.
* Header Commands::     Commands for moving headers or changing headers.
* Movement::            Moving around in message buffers.
* Insertion::           Inserting things into message buffers.
* MIME::                @acronym{MIME} considerations.
* IDNA::                Non-@acronym{ASCII} domain name considerations.
* Security::            Signing and encrypting messages.
* Various Commands::    Various things.
* Sending::             Actually sending the message.
* Mail Aliases::        How to use mail aliases.
* Spelling::            Having Emacs check your spelling.
@end menu


@node Buffer Entry
@section Buffer Entry
@cindex undo
@kindex C-_

You most often end up in a Message buffer when responding to some other
message of some sort.  Message does lots of handling of quoted text, and
may remove signatures, reformat the text, or the like---depending on
which used settings you're using.  Message usually gets things right,
but sometimes it stumbles.  To help the user unwind these stumblings,
Message sets the undo boundary before each major automatic action it
takes.  If you press the undo key (usually located at @kbd{C-_}) a few
times, you will get back the un-edited message you're responding to.


@node Header Commands
@section Header Commands

@subsection Commands for moving to headers

These following commands move to the header in question.  If it doesn't
exist, it will be inserted.

@table @kbd

@item C-c ?
@kindex C-c ?
@findex describe-mode
Describe the message mode.

@item C-c C-f C-t
@kindex C-c C-f C-t
@findex message-goto-to
Go to the @code{To} header (@code{message-goto-to}).

@item C-c C-f C-o
@kindex C-c C-f C-o
@findex message-goto-from
Go to the @code{From} header (@code{message-goto-from}).  (The ``o''
in the key binding is for Originator.)

@item C-c C-f C-b
@kindex C-c C-f C-b
@findex message-goto-bcc
Go to the @code{Bcc} header (@code{message-goto-bcc}).

@item C-c C-f C-f
@kindex C-c C-f C-f
@findex message-goto-fcc
Go to the @code{Fcc} header (@code{message-goto-fcc}).

@item C-c C-f C-c
@kindex C-c C-f C-c
@findex message-goto-cc
Go to the @code{Cc} header (@code{message-goto-cc}).

@item C-c C-f C-s
@kindex C-c C-f C-s
@findex message-goto-subject
Go to the @code{Subject} header (@code{message-goto-subject}).

@item C-c C-f C-r
@kindex C-c C-f C-r
@findex message-goto-reply-to
Go to the @code{Reply-To} header (@code{message-goto-reply-to}).

@item C-c C-f C-n
@kindex C-c C-f C-n
@findex message-goto-newsgroups
Go to the @code{Newsgroups} header (@code{message-goto-newsgroups}).

@item C-c C-f C-d
@kindex C-c C-f C-d
@findex message-goto-distribution
Go to the @code{Distribution} header (@code{message-goto-distribution}).

@item C-c C-f C-o
@kindex C-c C-f C-o
@findex message-goto-followup-to
Go to the @code{Followup-To} header (@code{message-goto-followup-to}).

@item C-c C-f C-k
@kindex C-c C-f C-k
@findex message-goto-keywords
Go to the @code{Keywords} header (@code{message-goto-keywords}).

@item C-c C-f C-u
@kindex C-c C-f C-u
@findex message-goto-summary
Go to the @code{Summary} header (@code{message-goto-summary}).

@item C-c C-f C-i
@kindex C-c C-f C-i
@findex message-insert-or-toggle-importance
This inserts the @samp{Importance:} header with a value of
@samp{high}.  This header is used to signal the importance of the
message to the receiver.  If the header is already present in the
buffer, it cycles between the three valid values according to RFC
1376: @samp{low}, @samp{normal} and @samp{high}.

@item C-c C-f C-a
@kindex C-c C-f C-a
@findex message-generate-unsubscribed-mail-followup-to
Insert a reasonable @samp{Mail-Followup-To:} header
(@pxref{Mailing Lists}) in a post to an
unsubscribed list.  When making original posts to a mailing list you are
not subscribed to, you have to type in a @samp{Mail-Followup-To:} header
by hand.  The contents, usually, are the addresses of the list and your
own address.  This function inserts such a header automatically.  It
fetches the contents of the @samp{To:} header in the current mail
buffer, and appends the current @code{user-mail-address}.

If the optional argument @code{include-cc} is non-@code{nil}, the
addresses in the @samp{Cc:} header are also put into the
@samp{Mail-Followup-To:} header.

@end table

@subsection  Commands to change headers

@table @kbd

@item C-c C-o
@kindex C-c C-o
@findex message-sort-headers
@vindex message-header-format-alist
Sort headers according to @code{message-header-format-alist}
(@code{message-sort-headers}).

@item C-c C-t
@kindex C-c C-t
@findex message-insert-to
Insert a @code{To} header that contains the @code{Reply-To} or
@code{From} header of the message you're following up
(@code{message-insert-to}).

@item C-c C-n
@kindex C-c C-n
@findex message-insert-newsgroups
Insert a @code{Newsgroups} header that reflects the @code{Followup-To}
or @code{Newsgroups} header of the article you're replying to
(@code{message-insert-newsgroups}).

@item C-c C-l
@kindex C-c C-l
@findex message-to-list-only
Send a message to the list only.  Remove all addresses but the list
address from @code{To:} and @code{Cc:} headers.

@item C-c M-n
@kindex C-c M-n
@findex message-insert-disposition-notification-to
Insert a request for a disposition
notification.  (@code{message-insert-disposition-notification-to}).
This means that if the recipient support RFC 2298 she might send you a
notification that she received the message.

@item M-x message-insert-importance-high
@kindex M-x message-insert-importance-high
@findex message-insert-importance-high
@cindex Importance
Insert an @samp{Importance} header with a value of @samp{high},
deleting headers if necessary.

@item M-x message-insert-importance-low
@kindex M-x message-insert-importance-low
@findex message-insert-importance-low
@cindex Importance
Insert an @samp{Importance} header with a value of @samp{low}, deleting
headers if necessary.

@item C-c C-f s
@kindex C-c C-f s
@findex message-change-subject
@cindex Subject
Change the current @samp{Subject} header.  Ask for new @samp{Subject}
header and append @samp{(was: <Old Subject>)}.  The old subject can be
stripped on replying, see @code{message-subject-trailing-was-query}
(@pxref{Message Headers}).

@item C-c C-f x
@kindex C-c C-f x
@findex message-cross-post-followup-to
@vindex message-cross-post-default
@cindex X-Post
@cindex cross-post
Ask for an additional @samp{Newsgroups} and @samp{FollowUp-To} for a
cross-post.  @code{message-cross-post-followup-to} mangles
@samp{FollowUp-To} and @samp{Newsgroups} header to point to group.
If @code{message-cross-post-default} is @code{nil} or if called with a
prefix-argument @samp{Follow-Up} is set, but the message is not
cross-posted.

@item C-c C-f t
@kindex C-c C-f t
@findex message-reduce-to-to-cc
Replace contents of @samp{To} header with contents of @samp{Cc} or
@samp{Bcc} header.

@item C-c C-f w
@kindex C-c C-f w
@findex message-insert-wide-reply
Insert @samp{To} and @samp{Cc} headers as if you were doing a wide
reply.

@item C-c C-f a
@kindex C-c C-f a
@findex message-add-archive-header
@vindex message-archive-header
@vindex message-archive-note
@cindex X-No-Archive
Insert @samp{X-No-Archive: Yes} in the header and a note in the body.
The header and the note can be customized using
@code{message-archive-header} and @code{message-archive-note}.  When
called with a prefix argument, ask for a text to insert.  If you don't
want the note in the body, set @code{message-archive-note} to
@code{nil}.

@end table


@node Movement
@section Movement

@table @kbd
@item C-c C-b
@kindex C-c C-b
@findex message-goto-body
Move to the beginning of the body of the message
(@code{message-goto-body}).

@item C-c C-i
@kindex C-c C-i
@findex message-goto-signature
Move to the signature of the message (@code{message-goto-signature}).

@item C-a
@kindex C-a
@findex message-beginning-of-line
@vindex message-beginning-of-line
If at beginning of header value, go to beginning of line, else go to
beginning of header value.  (The header value comes after the header
name and the colon.)  This behaviour can be disabled by toggling
the variable @code{message-beginning-of-line}.

@end table


@node Insertion
@section Insertion

@table @kbd

@item C-c C-y
@kindex C-c C-y
@findex message-yank-original
Yank the message that's being replied to into the message buffer
(@code{message-yank-original}).

@item C-c C-M-y
@kindex C-c C-M-y
@findex message-yank-buffer
Prompt for a buffer name and yank the contents of that buffer into the
message buffer (@code{message-yank-buffer}).

@item C-c C-q
@kindex C-c C-q
@findex message-fill-yanked-message
Fill the yanked message (@code{message-fill-yanked-message}).  Warning:
Can severely mess up the yanked text if its quoting conventions are
strange.  You'll quickly get a feel for when it's safe, though.  Anyway,
just remember that @kbd{C-x u} (@code{undo}) is available and you'll be
all right.

@item C-c C-w
@kindex C-c C-w
@findex message-insert-signature
Insert a signature at the end of the buffer
(@code{message-insert-signature}).

@item C-c M-h
@kindex C-c M-h
@findex message-insert-headers
Insert the message headers (@code{message-insert-headers}).

@item C-c M-m
@kindex C-c M-m
@findex message-mark-inserted-region
Mark some region in the current article with enclosing tags.
See @code{message-mark-insert-begin} and @code{message-mark-insert-end}.

@item C-c M-f
@kindex C-c M-f
@findex message-mark-insert-file
Insert a file in the current article with enclosing tags.
See @code{message-mark-insert-begin} and @code{message-mark-insert-end}.

@end table


@node MIME
@section MIME
@cindex MML
@cindex MIME
@cindex multipart
@cindex attachment

Message is a @acronym{MIME}-compliant posting agent.  The user generally
doesn't have to do anything to make the @acronym{MIME} happen---Message will
automatically add the @code{Content-Type} and
@code{Content-Transfer-Encoding} headers.

The most typical thing users want to use the multipart things in
@acronym{MIME} for is to add ``attachments'' to mail they send out.
This can be done with the @kbd{C-c C-a} command, which will prompt for
a file name and a @acronym{MIME} type.  If your Emacs supports drag
and drop, you can also drop the file in the Message buffer.

You can also create arbitrarily complex multiparts using the @acronym{MML}
language (@pxref{Composing, , Composing, emacs-mime, The Emacs MIME
Manual}).

@node IDNA
@section IDNA
@cindex IDNA
@cindex internationalized domain names
@cindex non-ascii domain names

Message is a @acronym{IDNA}-compliant posting agent.  The user
generally doesn't have to do anything to make the @acronym{IDNA}
happen---Message will encode non-@acronym{ASCII} domain names in @code{From},
@code{To}, and @code{Cc} headers automatically.

Until @acronym{IDNA} becomes more well known, Message queries you
whether @acronym{IDNA} encoding of the domain name really should
occur.  Some users might not be aware that domain names can contain
non-@acronym{ASCII} now, so this gives them a safety net if they accidently
typed a non-@acronym{ASCII} domain name.

@vindex message-use-idna
The @code{message-use-idna} variable control whether @acronym{IDNA} is
used.  If the variable is @code{nil} no @acronym{IDNA} encoding will
ever happen, if it is set to the symbol @code{ask} the user will be
queried (the default), and if set to @code{t} @acronym{IDNA} encoding
happens automatically.

@findex message-idna-to-ascii-rhs
If you want to experiment with the @acronym{IDNA} encoding, you can
invoke @kbd{M-x message-idna-to-ascii-rhs RET} in the message buffer
to have the non-@acronym{ASCII} domain names encoded while you edit the message.

Note that you must have @uref{http://www.gnu.org/software/libidn/, GNU
Libidn} installed in order to use this functionality.

@node Security
@section Security
@cindex Security
@cindex S/MIME
@cindex PGP
@cindex PGP/MIME
@cindex sign
@cindex encrypt
@cindex secure

Using the @acronym{MML} language, Message is able to create digitally
signed and digitally encrypted messages.  Message (or rather
@acronym{MML}) currently support @acronym{PGP} (RFC 1991),
@acronym{PGP/MIME} (RFC 2015/3156) and @acronym{S/MIME}.  Instructing
@acronym{MML} to perform security operations on a @acronym{MIME} part is
done using the @kbd{C-c C-m s} key map for signing and the @kbd{C-c C-m
c} key map for encryption, as follows.

@table @kbd

@item C-c C-m s s
@kindex C-c C-m s s
@findex mml-secure-message-sign-smime

Digitally sign current message using @acronym{S/MIME}.

@item C-c C-m s o
@kindex C-c C-m s o
@findex mml-secure-message-sign-pgp

Digitally sign current message using @acronym{PGP}.

@item C-c C-m s p
@kindex C-c C-m s p
@findex mml-secure-message-sign-pgpmime

Digitally sign current message using @acronym{PGP/MIME}.

@item C-c C-m c s
@kindex C-c C-m c s
@findex mml-secure-message-encrypt-smime

Digitally encrypt current message using @acronym{S/MIME}.

@item C-c C-m c o
@kindex C-c C-m c o
@findex mml-secure-message-encrypt-pgp

Digitally encrypt current message using @acronym{PGP}.

@item C-c C-m c p
@kindex C-c C-m c p
@findex mml-secure-message-encrypt-pgpmime

Digitally encrypt current message using @acronym{PGP/MIME}.

@item C-c C-m C-n
@kindex C-c C-m C-n
@findex mml-unsecure-message
Remove security related @acronym{MML} tags from message.

@end table

These commands do not immediately sign or encrypt the message, they
merely insert the proper @acronym{MML} secure tag to instruct the
@acronym{MML} engine to perform that operation when the message is
actually sent.  They may perform other operations too, such as locating
and retrieving a @acronym{S/MIME} certificate of the person you wish to
send encrypted mail to.  When the mml parsing engine converts your
@acronym{MML} into a properly encoded @acronym{MIME} message, the secure
tag will be replaced with either a part or a multipart tag.  If your
message contains other mml parts, a multipart tag will be used; if no
other parts are present in your message a single part tag will be used.
This way, message mode will do the Right Thing (TM) with
signed/encrypted multipart messages.

Since signing and especially encryption often is used when sensitive
information is sent, you may want to have some way to ensure that your
mail is actually signed or encrypted.  After invoking the above
sign/encrypt commands, it is possible to preview the raw article by
using @kbd{C-u C-c RET P} (@code{mml-preview}).  Then you can
verify that your long rant about what your ex-significant other or
whomever actually did with that funny looking person at that strange
party the other night, actually will be sent encrypted.

@emph{Note!}  Neither @acronym{PGP/MIME} nor @acronym{S/MIME} encrypt/signs
RFC822 headers.  They only operate on the @acronym{MIME} object.  Keep this
in mind before sending mail with a sensitive Subject line.

By default, when encrypting a message, Gnus will use the
``signencrypt'' mode, which means the message is both signed and
encrypted.  If you would like to disable this for a particular
message, give the @code{mml-secure-message-encrypt-*} command a prefix
argument, e.g., @kbd{C-u C-c C-m c p}.

Actually using the security commands above is not very difficult.  At
least not compared with making sure all involved programs talk with each
other properly.  Thus, we now describe what external libraries or
programs are required to make things work, and some small general hints.

@subsection Using S/MIME

@emph{Note!}  This section assume you have a basic familiarity with
modern cryptography, @acronym{S/MIME}, various PKCS standards, OpenSSL and
so on.

The @acronym{S/MIME} support in Message (and @acronym{MML}) require
OpenSSL.  OpenSSL performs the actual @acronym{S/MIME} sign/encrypt
operations.  OpenSSL can be found at @uref{http://www.openssl.org/}.
OpenSSL 0.9.6 and later should work.  Version 0.9.5a cannot extract mail
addresses from certificates, and it insert a spurious CR character into
@acronym{MIME} separators so you may wish to avoid it if you would like
to avoid being regarded as someone who send strange mail.  (Although by
sending @acronym{S/MIME} messages you've probably already lost that
contest.)

To be able to send encrypted mail, a personal certificate is not
required.  Message (@acronym{MML}) need a certificate for the person to whom you
wish to communicate with though.  You're asked for this when you type
@kbd{C-c C-m c s}.  Currently there are two ways to retrieve this
certificate, from a local file or from DNS.  If you chose a local
file, it need to contain a X.509 certificate in @acronym{PEM} format.
If you chose DNS, you're asked for the domain name where the
certificate is stored, the default is a good guess.  To my belief,
Message (@acronym{MML}) is the first mail agent in the world to support
retrieving @acronym{S/MIME} certificates from DNS, so you're not
likely to find very many certificates out there.  At least there
should be one, stored at the domain @code{simon.josefsson.org}.  LDAP
is a more popular method of distributing certificates, support for it
is planned.  (Meanwhile, you can use @code{ldapsearch} from the
command line to retrieve a certificate into a file and use it.)

As for signing messages, OpenSSL can't perform signing operations
without some kind of configuration.  Especially, you need to tell it
where your private key and your certificate is stored.  @acronym{MML}
uses an Emacs interface to OpenSSL, aptly named @code{smime.el}, and it
contain a @code{custom} group used for this configuration.  So, try
@kbd{M-x customize-group RET smime RET} and look around.

Currently there is no support for talking to a CA (or RA) to create
your own certificate.  None is planned either.  You need to do this
manually with OpenSSL or using some other program.  I used Netscape
and got a free @acronym{S/MIME} certificate from one of the big CA's on the
net.  Netscape is able to export your private key and certificate in
PKCS #12 format.  Use OpenSSL to convert this into a plain X.509
certificate in PEM format as follows.

@example
$ openssl pkcs12 -in ns.p12 -clcerts -nodes > key+cert.pem
@end example

The @file{key+cert.pem} file should be pointed to from the
@code{smime-keys} variable.  You should now be able to send signed mail.

@emph{Note!}  Your private key is now stored unencrypted in the file,
so take care in handling it.  Storing encrypted keys on the disk are
supported, and Gnus will ask you for a passphrase before invoking
OpenSSL.  Read the OpenSSL documentation for how to achieve this.  If
you use unencrypted keys (e.g., if they are on a secure storage, or if
you are on a secure single user machine) simply press @code{RET} at
the passphrase prompt.

@subsection Using PGP/MIME

@acronym{PGP/MIME} requires an external OpenPGP implementation, such
as @uref{http://www.gnupg.org/, GNU Privacy Guard}.  Pre-OpenPGP
implementations such as PGP 2.x and PGP 5.x are also supported.  One
Emacs interface to the PGP implementations, PGG (@pxref{Top, ,PGG,
pgg, PGG Manual}), is included, but Mailcrypt and Florian Weimer's
@code{gpg.el} are also supported.

@vindex gpg-temp-directory
Note, if you are using the @code{gpg.el} you must make sure that the
directory specified by @code{gpg-temp-directory} have permissions
0700.

Creating your own key is described in detail in the documentation of
your PGP implementation, so we refer to it.

If you have imported your old PGP 2.x key into GnuPG, and want to send
signed and encrypted messages to your fellow PGP 2.x users, you'll
discover that the receiver cannot understand what you send. One
solution is to use PGP 2.x instead (i.e., if you use @code{pgg}, set
@code{pgg-default-scheme} to @code{pgp}).  If you do want to use
GnuPG, you can use a compatibility script called @code{gpg-2comp}
available from
@uref{http://muppet.faveve.uni-stuttgart.de/~gero/gpg-2comp/}.  You
could also convince your fellow PGP 2.x users to convert to GnuPG.
@vindex mml-signencrypt-style-alist
As a final workaround, you can make the sign and encryption work in
two steps; separately sign, then encrypt a message.  If you would like
to change this behavior you can customize the
@code{mml-signencrypt-style-alist} variable.  For example:

@lisp
(setq mml-signencrypt-style-alist '(("smime" separate)
                                    ("pgp" separate)
                                    ("pgpauto" separate)
                                    ("pgpmime" separate)))
@end lisp

This causes to sign and encrypt in two passes, thus generating a
message that can be understood by PGP version 2.

(Refer to @uref{http://www.gnupg.org/gph/en/pgp2x.html} for more
information about the problem.)

@node Various Commands
@section Various Commands

@table @kbd

@item C-c C-r
@kindex C-c C-r
@findex message-caesar-buffer-body
Caesar rotate (aka. rot13) the current message
(@code{message-caesar-buffer-body}).  If narrowing is in effect, just
rotate the visible portion of the buffer.  A numerical prefix says how
many places to rotate the text.  The default is 13.

@item C-c C-e
@kindex C-c C-e
@findex message-elide-region
@vindex message-elide-ellipsis
Elide the text between point and mark (@code{message-elide-region}).
The text is killed and replaced with the contents of the variable
@code{message-elide-ellipsis}.  The default value is to use an ellipsis
(@samp{[...]}).

@item C-c C-z
@kindex C-c C-x
@findex message-kill-to-signature
Kill all the text up to the signature, or if that's missing, up to the
end of the message (@code{message-kill-to-signature}).

@item C-c C-v
@kindex C-c C-v
@findex message-delete-not-region
Delete all text in the body of the message that is outside the region
(@code{message-delete-not-region}).

@item M-RET
@kindex M-RET
@findex message-newline-and-reformat
Insert four newlines, and then reformat if inside quoted text.

Here's an example:

@example
> This is some quoted text.  And here's more quoted text.
@end example

If point is before @samp{And} and you press @kbd{M-RET}, you'll get:

@example
> This is some quoted text.

*

> And here's more quoted text.
@end example

@samp{*} says where point will be placed.

@item C-c M-r
@kindex C-c M-r
@findex message-rename-buffer
Rename the buffer (@code{message-rename-buffer}).  If given a prefix,
prompt for a new buffer name.

@item TAB
@kindex TAB
@findex message-tab
@vindex message-tab-body-function
If non-@code{nil} execute the function specified in
@code{message-tab-body-function}.  Otherwise use the function bound to
@kbd{TAB} in @code{text-mode-map} or @code{global-map}.

@end table


@node Sending
@section Sending

@table @kbd
@item C-c C-c
@kindex C-c C-c
@findex message-send-and-exit
Send the message and bury the current buffer
(@code{message-send-and-exit}).

@item C-c C-s
@kindex C-c C-s
@findex message-send
Send the message (@code{message-send}).

@item C-c C-d
@kindex C-c C-d
@findex message-dont-send
Bury the message buffer and exit (@code{message-dont-send}).

@item C-c C-k
@kindex C-c C-k
@findex message-kill-buffer
Kill the message buffer and exit (@code{message-kill-buffer}).

@end table



@node Mail Aliases
@section Mail Aliases
@cindex mail aliases
@cindex aliases

@vindex message-mail-alias-type
The @code{message-mail-alias-type} variable controls what type of mail
alias expansion to use.  Currently only one form is supported---Message
uses @code{mailabbrev} to handle mail aliases.  If this variable is
@code{nil}, no mail alias expansion will be performed.

@code{mailabbrev} works by parsing the @file{/etc/mailrc} and
@file{~/.mailrc} files.  These files look like:

@example
alias lmi "Lars Magne Ingebrigtsen <larsi@@ifi.uio.no>"
alias ding "ding@@ifi.uio.no (ding mailing list)"
@end example

After adding lines like this to your @file{~/.mailrc} file, you should
be able to just write @samp{lmi} in the @code{To} or @code{Cc} (and so
on) headers and press @kbd{SPC} to expand the alias.

No expansion will be performed upon sending of the message---all
expansions have to be done explicitly.


@node Spelling
@section Spelling
@cindex spelling
@findex ispell-message

There are two popular ways to have Emacs spell-check your messages:
@code{ispell} and @code{flyspell}.  @code{ispell} is the older and
probably more popular package.  You typically first write the message,
and then run the entire thing through @code{ispell} and fix all the
typos.  To have this happen automatically when you send a message, put
something like the following in your @file{.emacs} file:

@lisp
(add-hook 'message-send-hook 'ispell-message)
@end lisp

@vindex ispell-message-dictionary-alist
If you're in the habit of writing in different languages, this can be
controlled by the @code{ispell-message-dictionary-alist} variable:

@lisp
(setq ispell-message-dictionary-alist
      '(("^Newsgroups:.*\\bde\\." . "deutsch8")
        (".*" . "default")))
@end lisp

@code{ispell} depends on having the external @samp{ispell} command
installed.

The other popular method is using @code{flyspell}.  This package checks
your spelling while you're writing, and marks any mis-spelled words in
various ways.

To use @code{flyspell}, put something like the following in your
@file{.emacs} file:

@lisp
(defun my-message-setup-routine ()
  (flyspell-mode 1))
(add-hook 'message-setup-hook 'my-message-setup-routine)
@end lisp

@code{flyspell} depends on having the external @samp{ispell} command
installed.


@node Variables
@chapter Variables

@menu
* Message Headers::             General message header stuff.
* Mail Headers::                Customizing mail headers.
* Mail Variables::              Other mail variables.
* News Headers::                Customizing news headers.
* News Variables::              Other news variables.
* Insertion Variables::         Customizing how things are inserted.
* Various Message Variables::   Other message variables.
* Sending Variables::           Variables for sending.
* Message Buffers::             How Message names its buffers.
* Message Actions::             Actions to be performed when exiting.
@end menu


@node Message Headers
@section Message Headers

Message is quite aggressive on the message generation front.  It has to
be---it's a combined news and mail agent.  To be able to send combined
messages, it has to generate all headers itself (instead of letting the
mail/news system do it) to ensure that mail and news copies of messages
look sufficiently similar.

@table @code

@item message-generate-headers-first
@vindex message-generate-headers-first
If @code{t}, generate all required headers before starting to
compose the message.  This can also be a list of headers to generate:

@lisp
(setq message-generate-headers-first
      '(References))
@end lisp

@vindex message-required-headers
The variables @code{message-required-headers},
@code{message-required-mail-headers} and
@code{message-required-news-headers} specify which headers are
required.

Note that some headers will be removed and re-generated before posting,
because of the variable @code{message-deletable-headers} (see below).

@item message-draft-headers
@vindex message-draft-headers
When running Message from Gnus, the message buffers are associated
with a draft group.  @code{message-draft-headers} says which headers
should be generated when a draft is written to the draft group.

@item message-from-style
@vindex message-from-style
Specifies how @code{From} headers should look.  There are four valid
values:

@table @code
@item nil
Just the address---@samp{king@@grassland.com}.

@item parens
@samp{king@@grassland.com (Elvis Parsley)}.

@item angles
@samp{Elvis Parsley <king@@grassland.com>}.

@item default
Look like @code{angles} if that doesn't require quoting, and
@code{parens} if it does.  If even @code{parens} requires quoting, use
@code{angles} anyway.

@end table

@item message-deletable-headers
@vindex message-deletable-headers
Headers in this list that were previously generated by Message will be
deleted before posting.  Let's say you post an article.  Then you decide
to post it again to some other group, you naughty boy, so you jump back
to the @code{*post-buf*} buffer, edit the @code{Newsgroups} line, and
ship it off again.  By default, this variable makes sure that the old
generated @code{Message-ID} is deleted, and a new one generated.  If
this isn't done, the entire empire would probably crumble, anarchy would
prevail, and cats would start walking on two legs and rule the world.
Allegedly.

@item message-default-headers
@vindex message-default-headers
This string is inserted at the end of the headers in all message
buffers.

@item message-subject-re-regexp
@vindex message-subject-re-regexp
@cindex Aw
@cindex Sv
@cindex Re
Responses to messages have subjects that start with @samp{Re: }.  This
is @emph{not} an abbreviation of the English word ``response'', but is
Latin, and means ``in response to''.  Some illiterate nincompoops have
failed to grasp this fact, and have ``internationalized'' their software
to use abominations like @samp{Aw: } (``antwort'') or @samp{Sv: }
(``svar'') instead, which is meaningless and evil.  However, you may
have to deal with users that use these evil tools, in which case you may
set this variable to a regexp that matches these prefixes.  Myself, I
just throw away non-compliant mail.

Here's an example of a value to deal with these headers when
responding to a message:

@lisp
(setq message-subject-re-regexp
      (concat
       "^[ \t]*"
         "\\("
           "\\("
             "[Aa][Nn][Tt][Ww]\\.?\\|"     ; antw
             "[Aa][Ww]\\|"                 ; aw
             "[Ff][Ww][Dd]?\\|"            ; fwd
             "[Oo][Dd][Pp]\\|"             ; odp
             "[Rr][Ee]\\|"                 ; re
             "[Rr][\311\351][Ff]\\.?\\|"   ; ref
             "[Ss][Vv]"                    ; sv
           "\\)"
           "\\(\\[[0-9]*\\]\\)"
           "*:[ \t]*"
         "\\)"
       "*[ \t]*"
       ))
@end lisp

@item message-subject-trailing-was-query
@vindex message-subject-trailing-was-query
@vindex message-subject-trailing-was-ask-regexp
@vindex message-subject-trailing-was-regexp
Controls what to do with trailing @samp{(was: <old subject>)} in subject
lines.  If @code{nil}, leave the subject unchanged.  If it is the symbol
@code{ask}, query the user what do do.  In this case, the subject is
matched against @code{message-subject-trailing-was-ask-regexp}.  If
@code{message-subject-trailing-was-query} is t, always strip the
trailing old subject.  In this case,
@code{message-subject-trailing-was-regexp} is used.

@item message-alternative-emails
@vindex message-alternative-emails
A regexp to match the alternative email addresses.  The first matched
address (not primary one) is used in the @code{From} field.

@item message-allow-no-recipients
@vindex message-allow-no-recipients
Specifies what to do when there are no recipients other than
@code{Gcc} or @code{Fcc}.  If it is @code{always}, the posting is
allowed.  If it is @code{never}, the posting is not allowed.  If it is
@code{ask} (the default), you are prompted.

@item message-hidden-headers
@vindex message-hidden-headers
A regexp, a list of regexps, or a list where the first element is
@code{not} and the rest are regexps.  It says which headers to keep
hidden when composing a message.

@lisp
(setq message-hidden-headers
      '(not "From" "Subject" "To" "Cc" "Newsgroups"))
@end lisp

@item message-header-synonyms
@vindex message-header-synonyms
A list of lists of header synonyms.  E.g., if this list contains a
member list with elements @code{Cc} and @code{To}, then
@code{message-carefully-insert-headers} will not insert a @code{To}
header when the message is already @code{Cc}ed to the recipient.

@end table


@node Mail Headers
@section Mail Headers

@table @code
@item message-required-mail-headers
@vindex message-required-mail-headers
@xref{News Headers}, for the syntax of this variable.  It is
@code{(From Date Subject (optional . In-Reply-To) Message-ID Lines
(optional . User-Agent))} by default.

@item message-ignored-mail-headers
@vindex message-ignored-mail-headers
Regexp of headers to be removed before mailing.  The default is
@samp{^[GF]cc:\\|^Resent-Fcc:\\|^Xref:\\|^X-Draft-From:}.

@item message-default-mail-headers
@vindex message-default-mail-headers
This string is inserted at the end of the headers in all message
buffers that are initialized as mail.

@end table


@node Mail Variables
@section Mail Variables

@table @code
@item message-send-mail-function
@vindex message-send-mail-function
@findex message-send-mail-with-sendmail
@findex message-send-mail-with-mh
@findex message-send-mail-with-qmail
@findex message-smtpmail-send-it
@findex smtpmail-send-it
@findex feedmail-send-it
Function used to send the current buffer as mail.  The default is
@code{message-send-mail-with-sendmail}.  Other valid values include
@code{message-send-mail-with-mh}, @code{message-send-mail-with-qmail},
@code{message-smtpmail-send-it}, @code{smtpmail-send-it} and
@code{feedmail-send-it}.

@item message-mh-deletable-headers
@vindex message-mh-deletable-headers
Most versions of MH doesn't like being fed messages that contain the
headers in this variable.  If this variable is non-@code{nil} (which is
the default), these headers will be removed before mailing when sending
messages via MH.  Set it to @code{nil} if your MH can handle these
headers.

@item message-qmail-inject-program
@vindex message-qmail-inject-program
@cindex qmail
Location of the qmail-inject program.

@item message-qmail-inject-args
@vindex message-qmail-inject-args
Arguments passed to qmail-inject programs.
This should be a list of strings, one string for each argument.  It
may also be a function.

For e.g., if you wish to set the envelope sender address so that bounces
go to the right place or to deal with listserv's usage of that address, you
might set this variable to @code{'("-f" "you@@some.where")}.

@item message-sendmail-f-is-evil
@vindex message-sendmail-f-is-evil
@cindex sendmail
Non-@code{nil} means don't add @samp{-f username} to the sendmail
command line.  Doing so would be even more evil than leaving it out.

@item message-sendmail-envelope-from
@vindex message-sendmail-envelope-from
When @code{message-sendmail-f-is-evil} is @code{nil}, this specifies
the address to use in the @acronym{SMTP} envelope.  If it is
@code{nil}, use @code{user-mail-address}.  If it is the symbol
@code{header}, use the @samp{From} header of the message.

@item message-mailer-swallows-blank-line
@vindex message-mailer-swallows-blank-line
Set this to non-@code{nil} if the system's mailer runs the header and
body together.  (This problem exists on SunOS 4 when sendmail is run
in remote mode.)  The value should be an expression to test whether
the problem will actually occur.

@item message-send-mail-partially-limit
@vindex message-send-mail-partially-limit
@cindex split large message
The limitation of messages sent as message/partial.  The lower bound
of message size in characters, beyond which the message should be sent
in several parts.  If it is @code{nil}, the size is unlimited.

@end table


@node News Headers
@section News Headers

@vindex message-required-news-headers
@code{message-required-news-headers} a list of header symbols.  These
headers will either be automatically generated, or, if that's
impossible, they will be prompted for.  The following symbols are valid:

@table @code

@item From
@cindex From
@findex user-full-name
@findex user-mail-address
This required header will be filled out with the result of the
@code{message-make-from} function, which depends on the
@code{message-from-style}, @code{user-full-name},
@code{user-mail-address} variables.

@item Subject
@cindex Subject
This required header will be prompted for if not present already.

@item Newsgroups
@cindex Newsgroups
This required header says which newsgroups the article is to be posted
to.  If it isn't present already, it will be prompted for.

@item Organization
@cindex organization
@vindex message-user-organization
@vindex message-user-organization-file
This optional header will be filled out depending on the
@code{message-user-organization} variable.
@code{message-user-organization-file} will be used if this variable is
@code{t}.  This variable can also be a string (in which case this string
will be used), or it can be a function (which will be called with no
parameters and should return a string to be used).

@item Lines
@cindex Lines
This optional header will be computed by Message.

@item Message-ID
@cindex Message-ID
@vindex message-user-fqdn
@vindex mail-host-address
@vindex user-mail-address
@findex system-name
@cindex Sun
@cindex i-did-not-set--mail-host-address--so-tickle-me
This required header will be generated by Message.  A unique ID will be
created based on the date, time, user name and system name.  For the
domain part, message will look (in this order) at
@code{message-user-fqdn}, @code{system-name}, @code{mail-host-address}
and @code{message-user-mail-address} (i.e. @code{user-mail-address})
until a probably valid fully qualified domain name (FQDN) was found.

@item User-Agent
@cindex User-Agent
This optional header will be filled out according to the
@code{message-newsreader} local variable.

@item In-Reply-To
This optional header is filled out using the @code{Date} and @code{From}
header of the article being replied to.

@item Expires
@cindex Expires
@vindex message-expires
This extremely optional header will be inserted according to the
@code{message-expires} variable.  It is highly deprecated and shouldn't
be used unless you know what you're doing.

@item Distribution
@cindex Distribution
@vindex message-distribution-function
This optional header is filled out according to the
@code{message-distribution-function} variable.  It is a deprecated and
much misunderstood header.

@item Path
@cindex path
@vindex message-user-path
This extremely optional header should probably never be used.
However, some @emph{very} old servers require that this header is
present.  @code{message-user-path} further controls how this
@code{Path} header is to look.  If it is @code{nil}, use the server name
as the leaf node.  If it is a string, use the string.  If it is neither
a string nor @code{nil}, use the user name only.  However, it is highly
unlikely that you should need to fiddle with this variable at all.
@end table

@findex yow
@cindex Mime-Version
In addition, you can enter conses into this list.  The @sc{car} of this cons
should be a symbol.  This symbol's name is the name of the header, and
the @sc{cdr} can either be a string to be entered verbatim as the value of
this header, or it can be a function to be called.  This function should
return a string to be inserted.  For instance, if you want to insert
@code{Mime-Version: 1.0}, you should enter @code{(Mime-Version . "1.0")}
into the list.  If you want to insert a funny quote, you could enter
something like @code{(X-Yow . yow)} into the list.  The function
@code{yow} will then be called without any arguments.

If the list contains a cons where the @sc{car} of the cons is
@code{optional}, the @sc{cdr} of this cons will only be inserted if it is
non-@code{nil}.

If you want to delete an entry from this list, the following Lisp
snippet might be useful.  Adjust accordingly if you want to remove