Has "bounce" been removed from the Apple Mail AppleScript dictionary?

(Running Mavericks 10.9.5)

I have followed the instructions here on How to Bounce Emails in Mac OS X Mail. I am able to select the service and it runs without error but I don't see an email sent out in the Apple Mail Activity window and in a few tests bouncing mail to myself, I never receive the bounced mail.

I am looking in the Mail app's AppleScript dictionary for "bounce" and have not been able to find it. Has Apple removed the "bounce" feature entirely (and not just as a UI command)? If so, should I presume that the AppleScript "bounce" command below is failing silently? The message does get deleted

(Before anyone advises about not bouncing spam – I don't need this for spam, or at least typical spam. I need this because of having been added to some "BCC" mailing lists which it would be politically awkward for me to request removal from – such is my digital life. . .)

on run {input, parameters}

    tell application "Mail"

        repeat with eachMessage in input

            bounce eachMessage

            delete eachMessage

        end repeat

    end tell

end run