Find a message in a mailing list

funcs.el

(defun mu4e-action-find-in-mailing-list (msg)
  "Find message in mailing-list archives"
  (interactive)
  (let* ((mlist (mu4e-message-field msg :mailing-list))
         (msg-id (mu4e-message-field msg :message-id))
         (url
          (pcase mlist

            ;; gnu.org
            ((pred (lambda (x) (string-suffix-p "gnu.org" x)))
             (concat
              "https://lists.gnu.org/archive/cgi-bin/namazu.cgi?query="
              (concat
               (url-hexify-string
                (concat
                 "+message-id:<"
                 msg-id
                 ">"))
               "&submit=" (url-hexify-string "Search!")
               "&idxname="
               (replace-regexp-in-string "\.gnu\.org" "" mlist))))

            ;; google.groups
            ((pred (lambda (x) (string-suffix-p "googlegroups.com" x)))
             (concat
              "https://groups.google.com/forum/#!topicsearchin/"
              (replace-regexp-in-string "\.googlegroups\.com" "" mlist)
              "/messageid$3A"
              (url-hexify-string (concat "\"" msg-id "\"")))))))
    (when url
      (message "opening url: " url)
      (browse-url url))))