IT Troubleshooters

Whenever you send an email to someone in Outlook, it will add that person to your nickname cache for quicker access in the future.
If that person’s address changes, especially if that person is on your domain, you may find their old email address pops-up as a suggestion when you start typing in the person’s name in the To:, Cc: or Bcc: fields of a message. To clear your nickname cache so this doesn’t happen, follow the steps below.

Note: This will not affect your Global Address list or any of your contacts list. This merely deletes the cache which pops-up suggested email addresses when you start typing an address in Outlook.

1. Quit Outlook.
2. Start Microsoft Windows Explorer.
3. On the Tools menu, click Folder Options, and then click the View tab.
4. Under Advanced Settings, click to select the Show hidden files and folders check box.
5. Click OK.
6. Click Start, point to Search, and then click All files or folders.
7. In the Search Companion box, type *.NK2 in the All or part of the file name box: box.
8. In the Look In box, click to select your local hard disk.
9. Click Search.
10. Right-click the .NK2 file with the name of the profile that you want to reset, and then click Rename.
11. Rename the file to profilename.bak, and then press ENTER.
12. Quit Windows Explorer.
13. Restart Outlook.
Outlook will generate a new nickname cache.