Item: The ability to filter contacts in the Select Contact dialog by category. There is enough room in the dialog for a By Category… button. Use case: you want to send mail to several family members whose contact info is already tagged with a user-created category (“Family,” or the like). You open Select Contact , filter by category, and pick Family. With the list filtered, you then “select all,” right-click, then select Send Message… This would be quick and would not require first adding all the names to a distribution list.
Item: A New… menu item in the select-category dropdown list within the Contact dialog (I mean the dialog for editing an existing contact or adding a new one). This would be the equivalent of — and a shortcut to — Menu > Tools > Categories. If you create a new category, the dropdown list is updated and you can choose the new category immediately from the list.