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Delete unwanted 'nicknames' in Outlook

Nicknames aren't in your address book or from Active Directory. Learn how you can get rid of the outdated ones before they cause problems.

Outlook is smart. When you type a username into Outlook 97, 2000 and 2003, it tries to "guess" what username you are typing after a couple of keystrokes in the address field. Names will magically appear of people you have sent e-mails to in the past.

Microsoft refers to this feature internally as the "nickname" system. Nicknames are not derived from the address book or from Active Directory, but from input to the address fields. As a result, they are stored separately from both the user's address book and the Active Directory store itself.

As helpful as this feature can be, many users (and administrators) are not aware of it. Or, if they are aware of it, they may believe that the user name(s) called up by it are derived from the address book or Active Directory. As a result, users and admins alike may not notice that these names may be inaccurate or outdated. This can create problems: misdirected mail, user frustration and also slow Outlook load times if the nickname cache becomes excessively large.

You can deal with this problem in four different ways. One is to periodically delete the nickname cache, which is stored in \Windows\Application Data\Microsoft\Outlook\<profile name>.nick (or \Documents and Settings\ <profile name>\Application Data\Microsoft\Outlook\ <profile name>.nick). Outlook 2003 uses a file with the extension .NK2. Note that the profile folder may be hidden by default.

A second option is to disable the use of nicknames entirely. In Outlook, look in Tools | Options | Email Options | Advanced E-mail Options, and uncheck "Automatic name checking" under the When sending a message section.

A third option is to use a Microsoft utility for interactively deleting nicknames from the list, found at The fourth option is to educate users on how to manually prune the nickname list. When typing in a name in an address field, the nickname list that appears can be browsed by scrolling up or down. To delete a name from the list, simply move the highlight to the name in question and hit the Delete key.

Serdar Yegulalp is the editor of the Windows 2000 Power Users Newsletter.

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