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.
message-generate-headers-first ¶If t, generate all required headers before starting to
compose the message. This can also be a list of headers to generate:
(setq message-generate-headers-first
'(References))
The variables message-required-headers,
message-required-mail-headers and
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 message-deletable-headers (see below).
message-draft-headers ¶When running Message from Gnus, the message buffers are associated
with a draft group. message-draft-headers says which headers
should be generated when a draft is written to the draft group.
message-from-style ¶Specifies how From headers should look. There are four valid
values:
nilJust the address—‘king@grassland.com’.
parens‘king@grassland.com (Elvis Parsley)’.
angles‘Elvis Parsley <king@grassland.com>’.
defaultLook like angles if that doesn’t require quoting, and
parens if it does. If even parens requires quoting, use
angles anyway.
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 *post-buf* buffer, edit the Newsgroups line, and
ship it off again. By default, this variable makes sure that the old
generated 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.
message-default-headers ¶Header lines to be inserted in outgoing messages before you edit the message, so you can edit or delete their lines. If set to a string, it is directly inserted. If set to a function, it is called and its result is inserted.
message-subject-re-regexp ¶Responses to messages have subjects that start with ‘Re: ’. This is not an abbreviation of the English word “response”, but it comes from the Latin “res”, and means “in the matter of”. Some illiterate nincompoops have failed to grasp this fact, and have “internationalized” their software to use abominations like ‘Aw: ’ (“antwort”) or ‘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:
(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]*"
))
message-subject-trailing-was-query ¶Controls what to do with trailing ‘(was: <old subject>)’ in subject
lines. If nil, leave the subject unchanged. If it is the symbol
ask, query the user what to do. In this case, the subject is
matched against message-subject-trailing-was-ask-regexp. If
message-subject-trailing-was-query is t, always strip the
trailing old subject. In this case,
message-subject-trailing-was-regexp is used.
message-alternative-emails ¶Regexp or predicate function matching alternative email addresses. The first address in the To, CC or From headers of the original article matching this variable is used as the From field of outgoing messages, replacing the default From value.
For example, if you have two secondary email addresses john@home.net and john.doe@work.com and want to use them in the From field when composing a reply to a message addressed to one of them, you could set this variable like this:
(setq message-alternative-emails
(regexp-opt '("john@home.net" "john.doe@work.com")))
This variable has precedence over posting styles and anything that runs
off message-setup-hook.
message-allow-no-recipients ¶Specifies what to do when there are no recipients other than
Gcc or FCC. If it is always, the posting is
allowed. If it is never, the posting is not allowed. If it is
ask (the default), you are prompted.
A regexp, a list of regexps, or a list where the first element is
not and the rest are regexps. It says which headers to keep
hidden when composing a message.
(setq message-hidden-headers
'(not "From" "Subject" "To" "CC" "Newsgroups"))
Headers are hidden using narrowing, you can use M-x widen to expose them in the buffer.
message-header-synonyms ¶A list of lists of header synonyms. E.g., if this list contains a
member list with elements CC and To, then
message-carefully-insert-headers will not insert a To
header when the message is already CCed to the recipient.
message-syntax-checks ¶Controls what syntax checks should not be performed on outgoing posts. To disable checking of long signatures, for instance, add
(signature . disabled)
to this list.
Valid checks are:
approved ¶Check whether the article has an Approved header, which is
something only moderators should include.
continuation-headersCheck whether there are continuation header lines that don’t begin with whitespace.
control-charsCheck for invalid characters.
emptyCheck whether the article is empty.
existing-newsgroupsCheck whether the newsgroups mentioned in the Newsgroups and
Followup-To headers exist.
fromCheck whether the From header seems nice.
illegible-textCheck whether there is any non-printable character in the body.
invisible-textCheck whether there is any invisible text in the buffer.
long-header-linesCheck for too long header lines.
long-lines ¶Check for too long lines in the body.
message-idCheck whether the Message-ID looks syntactically ok.
multiple-headersCheck for the existence of multiple equal headers.
new-textCheck whether there is any new text in the messages.
newsgroupsCheck whether the Newsgroups header exists and is not empty.
quoting-styleCheck whether text follows last quoted portion.
repeated-newsgroupsCheck whether the Newsgroups and Followup-To headers
contains repeated group names.
reply-toCheck whether the Reply-To header looks ok.
sender ¶Insert a new Sender header if the From header looks odd.
sendsys ¶Check for the existence of version and sendsys commands.
shootCheck whether the domain part of the Message-ID header looks ok.
shorten-followup-toCheck whether to add a Followup-To header to shorten the number
of groups to post to.
signatureCheck the length of the signature.
sizeCheck for excessive size.
subjectCheck whether the Subject header exists and is not empty.
subject-cmsgCheck the subject for commands.
valid-newsgroupsCheck whether the Newsgroups and Followup-To headers
are valid syntactically.
All these conditions are checked by default, except for sender
for which the check is disabled by default if
message-insert-canlock is non-nil (see Canceling News).