Problem: A user would like to remove an invalid entry or duplicate name/e-mail address from their auto-complete list in Outlook. Solution:
https://support.office.com/en-us/article/Manage-suggested-recipients-in-the-To-Cc-and-Bcc-boxes-with-Auto-Complete-dbe46e31-c098-4881-8cf7-66b037bce23e