I would like to edit e-mail messages without the header (!) in message mode. If I open a file in message mode and it does not have the usual e-mail headers, then
M-q filling does not work as I discovered in this question. In that question I learned that the header separator can be customized, but what if there is no header and no header separator at all?
I understand that sending the mail will not work without this header, but I send the mail on a different route. Actually, this is part of trying to use Emacs as the external editor for MailMate which works fine, except that I have not found a mode in which I can edit e-mail with font-locking for quote depth etc. Probably this should be a minor mode for editing e-mail which does not exist yet. notmuch-mode, mu4e-mode and org-msg all seem to be based on message mode and behave the same wrt. the header.
So is it possible to use message mode without a header?