Not able to Execute AppleScript within “Mail” application

Question

I have create one mail plugin and add \"Button\" beside the \"Send\" button of outgoing Mail,

Answer 1

That menu item does have a keyboard shortcut, so you can use that too. Did you try this?

activate application "Mail"
tell application "System Events"
    tell application process "Mail"
        keystroke "d" using {command down, shift down}
    end tell
end tell