Applescript to automatically reply to an email

Question

Hi, I'm trying to create a script in Lion that will send an automatic reply to messages I receive with the subject line "Here's your offer". I am a BCC recipient of these messages, and I want to send the message to the actual recipient, not to the sender.
I created a rule to run an Applescript if the subject is "Here's your offer" but it's not doing anything. Even if it were working, I'm sure it's missing the code to send the message to the recipient in the To: field of the triggering message. I'd love some input on this script:
using terms from application "Mail"
          on perform mail action with messages theMessages for rule theRule
                    tell application "Mail"
                              repeat with thisMessage in theMessages
                                        set AppleScript's text item delimiters to {""}
                                        set thisSender to sender of theMessages
                                        set theNewMessage to reply thisMessage with opening window
                                        tell theNewMessage
                                                  set content to "Test message"
                                        end tell
  send theNewMessage
                              end repeat
                    end tell
          end perform mail action with messages
end using terms from

Answer 1

It is possible to create a new mail message using Applescript, and to send the message, or to bring up the new message window for further editing before sending. If, however, you start with the new message window (or a reply window, effectively the same thing) I don't think it is possible to have Applescript manipulate the new message, as there is no reference to it.
Unless your "boiler plate" text is very long, I would suggest looking at TextExpander. I strted using it back when it was freeware, but it has since gone commercial, for around $30, I think. It is a keystroke monitor, and when it sees keystroke sequences which you define it automatically replaces them with (or appends to them - your choice) predefined text. I don't know how long the replacement text can be - I only use short sequences - but you can have any number of sequences. So for example I type a.k.z (dots inserted to stop it working!) and it replaces it with my initials and the html link to my elephant icon. If you go for it I would recommend giving all your sequences the same pattern - mine are all two characters followed by z, so that ordinary words don't get accidentally substituted.
AK