Capture Attribute Indicator in VM for Org Mode Captured Emails

Problem -- adding an attribute indicator in the vm summary buffer for emails I have org mode-captured some action/actions from. Due to old age(?) I now and then tend to forget if I have added items on my GTD-lists from an email, which sometime generates duplicate items or more...

The quick solution I came up with was to

1. add a user-defined label, captured, to the email I just captured some action from, and
2. modify the vm summary format with a user defined specifier to show the character C next to the attribute indicators if the email has the captured label.

The first step was really really easy thanks to org-capture-after-finalize-hook, in .emacs I did

;; Add a hook to the label-setting-function.
(add-hook 'org-capture-after-finalize-hook
          'ra/vm-add-captured-message-label)

;; Add a label to the current email, may also reside in .vm
(defun ra/vm-add-captured-message-label ()
  "Adds the \"captured\" label to the current email."
 (if (equal "mairix" (plist-get org-store-link-plist :type))
     ;;
     ;; if you do not use mairix-type links you can
     ;; - comment out the equal-condition above, and
     ;; - comment in the or-condition below.
     ;;
     ;; (or (eq major-mode 'vm-summary-mode)
     ;;     (eq major-mode 'vm-presentation-mode))
     ;;
     (vm-add-message-labels "captured" 1)))

The second step was also quite straight forward, in .vm I added

;; VM summary template
(setq vm-summary-format
      "%n %*%a%1UC %-17.17F %-3.3m %2d %S %I\"%s\"\n")

;; VM summary function C
(defun vm-summary-function-C (message)
  "Given a VM message, returns a \"C\" if it has been labelled
  \"captured\"."
  (if (member "captured" (vm-labels-of message))
      "C"
    ""))

In the vm-summary-format template above, note the sequence %a%1UC where

• %a is the usual attribute indicators, and 
• %1UC is where the vm-summary-function-C is called and my custom "attribute indicator", the single C character, may be inserted.

To conclude -- I did not add a new attribute and attribute indicator, but my own custom user-defined label, captured, and my own custom user-defined label indicator, C.

This solution is far from perfect, eg capturing anything else while being in a vm summary or presentation buffer will get the current email labelled. An alternative would then be to create a new capture template and key combo for capturing emails... but that will probably mess things up for me, hitting the correct combo in the correct buffer... :P

Finally a rowshot from vm summary after capturing, indicator R for replied and C for captured:

->  6    R C Robert Adesam     Jun 21 50 "Emacs for Linguists"