Participate in this discussion via email (and layout of the box)

Ho on earth do I translate the above string?

I have just upgraded and have tried creating a new .po file, but the string is not there.

Is it dealt with by postmatic?

Also, can we get the checkbox ("Participate in this discussion via email") BOVE the "Send" button? That way many more people will remember to subscribe.

Thanks a lot for all your help and for a great plugin.