Configure mu4e for Gmail-style citation (reply quoting)

Question

I want to configure mu4e citation style—the manner in which mu4e quotes the thread in a reply—so that it is compatible with Gmail's UI.

Note the triple-dot collapsed style in the second message, where I replied through the UI.

There are the message contents:

Content-Type: text/plain; charset="UTF-8"

This style does

On Wed, Oct 3, 2018 at 5:52 PM <matt@example.com> wrote:

>
> This style doesn't work
>
> matt@example.com writes:
>
> > test
>

I have tried setting (setq message-cite-style message-cite-style-gmail), but no luck.

Answer 1

You need to customize message-citation-line-function. Something like this would help (it may require date formatting to please your needs):

(defun my/message-insert-citation-line ()
  "Based off `message-insert-citation-line`."
  (when message-reply-headers
    (insert "On " (mail-header-date message-reply-headers) " ")
    (insert (mail-header-from message-reply-headers) " writes:")
    (newline)
    (newline)))

(setq message-citation-line-function 'my/message-insert-citation-line)

Answer 2

An alternative to the above:

(setq message-citation-line-format "On %d %b %Y at %R, %f wrote:\n")

followed by

(setq message-citation-line-function 'message-insert-formatted-citation-line)

Answer 3

(with-eval-after-load 'message
  (setq message-cite-style message-cite-style-gmail)
  (setq message-citation-line-function 'message-insert-formatted-citation-line)
  (setq message-citation-line-format "On %a, %b %e, %Y at %I:%M %p %f wrote:"))

(use-package messages-are-flowing
  :ensure t
  :hook ((message-mode . messages-are-flowing-use-and-mark-hard-newlines)))

This is something that is working for me so far. I have had so much trouble though. I am really dubious that it's going to work for all emails.

Also, I'm not using m4ue. I'm using notmuch and message mode so beware.