Clear the Auto-Complete Email Address Cache in Outlook

Outlook 2003 and Outlook 2007 have an automatic completion for any email address that you try to type into the To or CC fields. This feature does not pull from the contacts or address book. You may have tried to email somebody that wasn’t in your contact list. It will still add that to the auto complete list.

The problem comes in when you put in a bad address, and then every time you want to type in the email address, the incorrect one appears in the auto complete list.

To fix this problem, there are two ways around this. The easiest way is this:

  1. Start typing in the address that shows up incorrectly.
  2. Hit the Down arrow key to select the auto completed address.
  3. Hit the Delete key to delete the auto complete address

The other way is by opening the profile folder and deleting the .nk2 file.

  1. Open up windows explorer, and paste the following into the address bar:
  2. %APPDATA%\Microsoft\Outlook
  3. Delete the Outlook.NK2 file that you find in this folder.