Key shortcut for clipping emails

I have been using the key shortcut for clipping individual emails (Ctrl-Alt-Cmd M) for ages but have now lost it following a problem with installation of a mail security package. I’ve now deleted this package, but cannot find a way of reinstating the script shortcut. This is obviously something simple but I would welcome being pointed in the right direction.

Did you try Help > Install Add-ons?

No, I didn’t and yes, it does. It’s one of those situations where you scour the menus and don’t see the obvious. Thanks for the prompt response.