Categorize Contacts with bad addresses

Outlook doesn't have an automated method for assigning categories or deleting contacts that contain bad addresses, but you can use VBA to assign categories or delete the contacts.

How to Upgrade to Color Categories

After upgrading to Outlook 2013, 2010, or 2007, users need to convert categories to color categories to add their categories to the master category list.

Categories vs. Multiple Contacts Folders

You'll find some debate over which method is better for managing different types of contacts — have more than one Contacts folder (Personal, Business, etc.) or use one Contacts folder with categories. There are pluses and minuses for both. Personally, I use a combination. I have a couple of separate Contacts folders that use special  

Understanding Outlook's Calendar patchwork colors

Users often complain about the patchwork coloring in Outlook's calendar. This is caused by setting All Day Events to Show time as Busy and setting a color category on the item. Tentative, Working elsewhere, and Out-of-office also add color to the days.