The one thing that many of my clients used extensively with our previous webmail system was message highlighting. The ability to choose a hexidecimal color (i.e. #FFFF00, etc) for a particular message based on criteria such as "From", "Subject" content, etc. So basically, if I want to identify all of my messages from "Bob Smith" by highlighting them in yellow, I could do that. And "Suzie Jenkins" could be a light green highlight. This really could be a hack that's not too extensive. I imagine with a little time and focus, I could even toss it together. However, I would love to see it as an added feature so I wouldn't have to continually modify the source code when I update to a new version.
What does everyone think about something like this? Thanks.