mu4e: move messages to spam folder

email.el

@@ -48,6 +48,8 @@
         mu4e-drafts-folder  "/mailbox/Drafts"
         mu4e-trash-folder   "/mailbox/Trash"
         mu4e-refile-folder  "/mailbox/Archive"
+        ;; TODO create context-aware variable
+        mu4e-spam-folder  "/mailbox/Junk"
         mu4e-compose-signature nil
         mu4e-maildir-shortcuts (list (list :maildir "/mailbox/Inbox"
                                            :key ?i)
@@ -92,6 +94,21 @@
                         ;; IMAP-deleted:
                         (mu4e--server-move docid (mu4e--mark-check-target target) "+S-u-N"))))
 
+  (add-to-list 'mu4e-marks
+               '(spam
+                 :char "S"
+                 :prompt "Spam"
+                 :shot-target (lambda (target) mu4e-spam-folder)
+                 :action (lambda (docid msg target)
+                        (mu4e--server-move docid mu4e-spam-folder "+S-u-N"))))
+
+  (defun my:mu4e-mark-for-spam()
+    "Mark as read and move to spam."
+    (interactive)
+    (mu4e-headers-mark-and-next 'spam))
+
+  (map! :map mu4e-headers-mode-map :n "S" #'my:mu4e-mark-for-spam)
+
   (add-to-list 'mu4e-view-mime-part-actions
     '(:name "calendar"
       :handler (lambda (file)