Outlook does not add recipients to the Auto-Complete cache

First, make sure that the Auto-Complete feature is enabled. To do this, follow these steps:

Outlook 2013 or Outlook 2010

1. Click File, and then click Options.
2. Select the Mail tab.
3. Scroll approximately halfway down until you see Send messages. Make sure that the Use Auto-Complete List to suggest names when typing in the To, Cc, and Bcc lines box is checked. The screen shot for this step is listed below).
   
   

Outlook 2007

1. Click Tools, and then click Options.
2. Click the E-mail options button.
3. Click the Advanced E-mail Options button.
4. Make sure that the Suggest names while completing To, Cc, and Bcc fields box is checked. (The screen shot for this step is listed below).
   
   

If the Auto-Complete feature is enabled and you are experiencing the behavior that is mentioned in the "Symptoms" section, the Auto-Complete cache may be damaged. The Auto-Complete cache cannot be repaired. It must be deleted.

For more information about clearing the Auto-Complete cache, click the following article number to view the article in the Microsoft Knowledge Base: Note The steps in the article clears all recipients previously written to the cache.