By default, names of people in mail messages, views, and folders are "online aware," that is, online status icons beside names show whether you can use instant messaging to chat with people or include them in instant meetings. If you don’t want this feature, use Preferences to turn it off.
1. Choose File - Preferences - User Preferences.
2. Click Instant Messaging - General.
3. Select or deselect "Show instant messaging status for names."
See Also