Automator action for sending draft mails via iCal event

Have you tried a Send Outgoing Messages action as your third action instead of the run applescript action?

I found this on MacScripter by a member regulus6633. Big thanks to him. You need to have Enable access for assistive devices turned on. You can find it in System Preferences under Universal Access. No need for the Mail actions :

Code:

try
	tell application "Mail"
		activate
		set the_messages to (every message of mailbox "sendlater")
		set mess_viewer to first message viewer
		set selected mailboxes of mess_viewer to {mailbox "sendlater"}
		repeat with this_mess in the_messages
			set selected messages of mess_viewer to (this_mess as list)
			tell application "System Events" to tell process "Mail"
				delay 0.2
				keystroke "d" using command down & shift down
				delay 0.2
				keystroke "d" using command down & shift down
			end tell
		end repeat
	end tell
	--	end if
	return this_mess
on error TheError
	tell me to activate
	display alert "An error has occurred:" message TheError as warning giving up after 20
end try