Article ID: 2802193 - View products that this article applies to.
As you add recipients to a new email message, Microsoft Outlook does not automatically suggest complete email addresses. You notice that after you send an email message to specific recipients, Outlook does not add those recipients to the Auto-Complete cache.
The Auto-Complete cache may be corrupted. When this occurs, Outlook may be unable add new recipients to the cache. If recipients are not added to the cache, Outlook cannot make a suggestion to automatically complete the email address.
First, make sure that the Auto-Complete feature is enabled. To do this, follow these steps:
Outlook 2013 or Outlook 2010
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:
287623Note The steps in the article clears all recipients previously written to the cache.
(http://support.microsoft.com/kb/287623/ )How to reset the nickname and the automatic completion caches in Outlook
Microsoft Outlook maintains a nickname cache that is used by both the automatic name checking feature and the AutoComplete feature. The nickname list is automatically generated as you send email messages from Outlook.