Checkdoc fixes in mail/*.el

* lisp/mail/feedmail.el (feedmail-mail-send-hook-splitter)
(feedmail-queue-runner-message-sender):
* lisp/mail/mail-extr.el (mail-extr-nuke-outside-range):
* lisp/mail/rmail.el (rmail-automatic-folder-directives)
(rmail-summary-displayed):
* lisp/mail/rmailmm.el (rmail-mime-searching):
* lisp/mail/sendmail.el (mail-mode):
* lisp/mail/supercite.el (sc-mail-last-header-nuked-p): Checkdoc fixes.

lisp/mail/feedmail.el

@@ -1318,7 +1318,7 @@ Then add the functions you want called to either
 `feedmail-mail-send-hook-queued' or `feedmail-mail-send-hook', as
 appropriate.  The distinction is that `feedmail-mail-send-hook'
 will be called when you send mail from a composition
-buffer (typically by typing C-c C-c), whether the message is sent
+buffer (typically by typing \\`C-c C-c'), whether the message is sent
 immediately or placed in the queue or drafts directory.
 `feedmail-mail-send-hook-queued' is called when messages are
 being sent from the queue directory, typically via a call to
@@ -1443,10 +1443,11 @@ Called for each message read back out of the queue directory with a
 single argument, the optional argument used in the call to
 `feedmail-run-the-queue' or `feedmail-run-the-queue-no-prompts'.
 Interactively, that argument will be the prefix argument.
-Most people want `mail-send' (bound to C-c C-s in mail-mode), but here's
+\\<mail-mode-map>
+Most people want `mail-send' (bound to \\[mail-send] in `mail-mode'), but here's
 your chance to have something different.  The default value is just a
 wrapper function which discards the optional argument and calls
-mail-send.  If you are a VM user, you might like vm-mail-send, though
+`mail-send'.  If you are a VM user, you might like vm-mail-send, though
 you really don't need that.  Called with funcall, not call-interactively."
   :version "24.1"			; changed default
   :group 'feedmail-queue

lisp/mail/mail-extr.el

@@ -618,7 +618,7 @@ Unless NO-REPLACE is true, at each of the positions in LIST-SYMBOL
  which lie outside of the range, one character at that position is
  replaced with a SPC."
   (or (memq no-replace '(t nil))
-      (error "no-replace must be t or nil, evaluable at macroexpand-time"))
+      (error "`no-replace' must be t or nil, evaluable at macroexpand-time"))
   `(let ((temp ,list-symbol)
 	   ch)
        (while temp

lisp/mail/rmail.el

@@ -519,8 +519,7 @@ For a given message, Rmail applies only the first matching directive.
 
 Examples:
   (\"/dev/null\" \"from\" \"@spam.com\") ; delete all mail from spam.com
-  (\"RMS\" \"from\" \"rms@\") ; save all mail from RMS.
-"
+  (\"RMS\" \"from\" \"rms@\") ; save all mail from RMS."
   :group 'rmail
   :version "21.1"
   :type '(repeat (sexp :tag "Directive")))
@@ -4315,7 +4314,7 @@ In fact, the non-nil value returned is the summary buffer itself."
        rmail-summary-buffer))
 
 (defun rmail-summary-displayed ()
-  "t if in RMAIL buffer and an associated summary buffer is displayed."
+  "Return t if in RMAIL buffer and an associated summary buffer is displayed."
   (and rmail-summary-buffer (get-buffer-window rmail-summary-buffer)))
 
 (defcustom rmail-redisplay-summary nil

lisp/mail/rmailmm.el

@@ -170,7 +170,7 @@ The value is usually nil, and bound to non-nil while inserting
 MIME entities.")
 
 (defvar rmail-mime-searching nil
-  "Bound to T inside `rmail-search-mime-message' to suppress expensive
+  "Bound to t inside `rmail-search-mime-message' to suppress expensive
 operations such as HTML decoding")
 
 ;;; MIME-entity object

lisp/mail/sendmail.el

@@ -671,8 +671,8 @@ switching to, the `*mail*' buffer.  See also `mail-setup-hook'."
   "Major mode for editing mail to be sent.
 Like Text Mode but with these additional commands:
 
-\\[mail-send]  mail-send (send the message)
-\\[mail-send-and-exit]  mail-send-and-exit (send the message and exit)
+\\[mail-send]  `mail-send' (send the message)
+\\[mail-send-and-exit]  `mail-send-and-exit' (send the message and exit)
 
 Here are commands that move to a header field (and create it if there isn't):
 	 \\[mail-to]  move to To:	\\[mail-subject]  move to Subj:
@@ -681,9 +681,9 @@ Here are commands that move to a header field (and create it if there isn't):
          \\[mail-mail-reply-to]  move to Mail-Reply-To:
          \\[mail-mail-followup-to] move to Mail-Followup-To:
 \\[mail-text]  move to message text.
-\\[mail-signature]  mail-signature (insert `mail-signature-file' file).
-\\[mail-yank-original]  mail-yank-original (insert current message, in Rmail).
-\\[mail-fill-yanked-message]  mail-fill-yanked-message (fill what was yanked).
+\\[mail-signature]  `mail-signature' (insert `mail-signature-file' file).
+\\[mail-yank-original]  `mail-yank-original' (insert current message, in Rmail).
+\\[mail-fill-yanked-message]  `mail-fill-yanked-message' (fill what was yanked).
 \\[mail-insert-file] insert a text file into the message.
 \\[mail-add-attachment] attach to the message a file as binary attachment.
 Turning on Mail mode runs the normal hooks `text-mode-hook' and

lisp/mail/supercite.el

@@ -727,7 +727,7 @@ If optional ATTRIBS-P is non-nil, the key/value pair is placed in
 
 ;; mail header nuking
 (defvar sc-mail-last-header-nuked-p nil
-  "True if the last header was nuked.")
+  "Non-nil if the last header was nuked.")
 
 (defun sc-mail-nuke-line ()
   "Nuke the current mail header line."