- Click on the File tab and select Options.
- Click on the Mail button.
- Scroll down to the Send messages section.
- Click the Empty Auto-Complete List button.
- A box will pop up asking if this is really what you want to do. Click Yes.
- Click OK to close the Outlook Options dialog.
For how to clear the Auto-Complete Cache in Outlook 2003 and 2007, click here.
For more assistance contact Technical Support here.