Microsoft Outlook maintains a list of formerly used email addresses which is used for the automatic completion feature. If one of these “nicknames” becomes corrupted it can cause any emails to that address to bounce. If this happens, the proper way to fix itis is to delete the corrupted entry and retype the email address in the To… field.
How to remove a corrupted nickname cache entry
- Open a new email message.
- Type the first few characters of the nickname cache entry that you want to remove from the cache.
- When the entry appears in the list of suggested names, use the Up and Down arrow keys on your keyboard to move the highlight to the entry you want to remove.
- Hit the Delete key on your keyboard to remove it from the list.