I was pretty sure I wasn't the only mutt user who missed having mail notifications in the indicator area. From a quick google search, it turns out I was in good company. Even better, a fellow by the name of Brad Mont actually wrote a basic python script to create an appindicator that would monitor a maildir. It was about 90% of what I was looking for.

Unfortunately, I didn't want another icon crowding the panel, so I adapted his script to use the messaging menu, so it shows up with chat (and any other communications programs). I made a few other changes along the way (notifications). Thanks to the folks who wrote gm-notify for being such an easy to read example of both notification and the messaging menu.

My version is available as maildir-indicator on gitorious. Hopefully it will be of use to others as well.