One feature I've always loved in email clients is the ability to color code messages (even though I'm colorblind!). In MacOE, you do this by creating a rule that can set the color of messages. In Entourage, you do it by setting the category of a message. Each category has a color associated with it, and any item in that category shows up with that color. The really nice part is that if you categorize a contact, any mail you get from those contacts are automatically categorized. I categorize my contacts with categories like work, friends, family, and newsletters. Most of the mail in my in box is then color coded so I can easily see who it's from.

I was always disappointed that Outlook categories don't have color coding, and I couldn't find a rule to set the color of messages. A recent lockergnome article showed me how to color code messages. I'd always thought of the color of a message as a property of the message, so I'd never found this functionality in Outlook. However, Outlook considers the color coding rules as a view setting for a folder. To set the color coding rules, go to Tools->Organize. This opens up a pane that gives you some organization options. One is "Using Colors". Here you can set up rules to color messages sent directly to you, or from or to specific people. It looks a bit tedious to set up lots of coloring rules, but it's great to know it's possible! It's another example of how Outlook can do just about anything if you can find the right entry point :-)

Update: I just noticed that the "Advanced Formatting..." button in the Tools->Organize pane gives you much more advanced ways to control how different items appear including the ability to do it based on category, once again reinforcing my last statement about Outlook being able to do just about anything if you find the right entry point!

Update 2: Tools->Organize is disabled for hotmail folders :-(