When sending an image via email from Lightroom 4 I would prefer that Lightroom handle the entire process and not launch the desktop email application. To that end I would like to be able to enter and format text within the Lightroom dialog, just as I can if I use a web based email service.
Having done this in the past, I know that no one, including Adobe, wants to get into the business of creating yet another RFC 2821 mail user agent. It is a thankless job that will literally eat resources and provide very little user value.
The best solution is to set up a Gmail account and send /from/ that. This does not use a local MUA, and just uses the remote server to send the mail.