Recently I started working on a Windows based system and, by extension, Outlook. I'm not really a power email user and I can get by with just about any email client...as long as I can provide rules for emails so that my inbox isn't chock-full of crap. Fortunately, Outlook 2010 fully supports a wide variety of rules that should be able to handle just about any weird email routing you want. Overall, I really like the rule support provided by Outlook.
However, the support provided for group based rules is absolutely horrendous and the complete opposite of a good user experience. You see, Outlook has the ability to store and manage contacts...to include creating a group of contacts. You can email everybody in the group or setup a rule to route emails from the group to a specific folder. But, if you create a group-based rule Outlook throws up all over itself and says that the group must be converted into a list of individual contacts. The rub comes when you add, or remove, a contact from a group. The associated group-based rule doesn't get updated. You have to literally go in and change each group-based rule to properly reflect your updates, which is itself a multiple step process.
Why is this the case? Contact management is not a technically difficult endeavor; it is basically a database storing some information and a GUI to make changes to the database. Why is it that Outlook rules cannot handle true group-based rules?