Make the Message System pop up without taking up the whole window.
When I click the message icon from the home screen of Learning Suite, the message window takes up the whole screen. I would prefer the message window to pop up in a modal format, or some other way that doesn't take up the whole screen and that loads more quickly.
Reason: Often, the messages aren't critical, and it feels like more of a distraction if I "navigate to another window" (which is what the experience feels like) and then realize the message wasn't important and I have to "navigate back". Perhaps the message could open up in a "chat" format as a sidebar, or some other way that doesn't completely take the user away from Learning Suite.
When you click on the mail icon in the top right, it doesn't take you to a new page, it hides the current page with a section that acts like a page. The 'x' in the top right is really bizarre for web applications (at least when it isn't apparent that there is something behind it). Reading feedback on an assignment is the same way. It makes you feel like you've navigated to a new page, when you really haven't.
One of the issues with this design pattern is the browser's back button. When a user's view changes from one page to something that looks like a new page, I think the first instinct would be to click "back" rather than looking for the blue/white X in the top right of a window. Maybe you could make it red instead, which is more conventional for "exit".
I think the user experience gains from handling this type of navigation in a more conventional way outweigh the ease that comes with throwing everything in a full-page container. At least make the container a little bit smaller so that we know it's an overlay/modal, not a new page.