You may have created the category by typing it in the Categories box of an item. If you want a category to be available to all items, the category must appear in the Master Category List (Master Category List: The list of categories that you can use to group items or to find items. This list contains general categories such as Business, Personal, and Phone Calls. You can add categories to and delete categories from this list.). Add the category to the Master Category List.

If you assigned items to the category by opening the items and typing a category name instead of selecting the category from the Available categories list in the Categories dialog box, you may have spelled the category a different way. Category names must be spelled consistently for every item assigned to the same category.

When you delete a category from the Master Category List (Master Category List: The list of categories that you can use to group items or to find items. This list contains general categories such as Business, Personal, and Phone Calls. You can add categories to and delete categories from this list.), the category is not deleted from items you have assigned to it. To do this, you must also remove the category from each item in that category.

You may have received an e-mail message that was assigned to a category by the sender. When you select the message, the category it is assigned to appears in the Available categories list in the Categories dialog box.