Here are the steps to remove entries from the AutoComplete cache
- Open a new email message.
- Type the first few characters of the AutoComplete entry that you want to remove.
- When the entry appears in the list of suggested names, move your mouse pointer over the name until it becomes highlighted, but do not click the name.
- When the “X” icon appears next to the highlighted name, click X to remove the name from the list, or press the Delete key on the keyboard.
To disable AutoComplete or clear your AutoComplete completely in Outlook.
In Outlook 2010 - 2016, follow the steps below to have this completely disabled. This is a sort of required in order not to send an email to a wrong recipient. - click the File menu and - select Options. - In the Outlook Options window click the Mail tab. - Scroll down to Send messages. - Uncheck the Use Auto-Complete List to suggest names when typing in the To, Cc, and Bcc lines box.
Note: To clear the AutoComplete list, simply click the Empty AutoComplete List button. You’ll see a confirmation window about clearing the AutoComplete list, click Yes.
Outlook AutoComplete should be completely disabled and any history that was in the auto-complete list should be completely erased (if you clicked the clear autocomplete button).