Changing the subject of the email for "immediate" notifications to the post title is a critical issue for me. +1

Also, for these "immediate" emails at least, I'd remove much of the "decoration" ASCII art and boilerplate. Just the content, please. Having the posted content up front means I can see what the discussion is about from the email summary, rather than always seeing "Greetings, Tom Woodfin" which has an information content of 0.