If you use Outlook 2010 or 2013, you will receive email bouncebacks if you use the auto-fill feature to email someone that you previously emailed.
You can remove them individually by typing in their email address and then pressing the “DELETE” key to remove them, or you can remove all auto-complete entries by doing the following:
- Open Outlook 2010 or 2013
- Click the “File” button in the top-left corner and then choose “Options”
- Click the “Mail” tab on the left-side menu
- Under the “Send Messages” section (about half-way down), click the “Empty Auto-Complete List” button and then click “Yes.”