Could not complete the operation. One or more parameter values are not valid.
Error resolution for the above problem.
1. When forwarding the message in To, Cc or Bcc address list automatically appears when you type the single letter, simply hover the mouse over it and press DEL key. This will remove it from the cache.
2. To clear out all of your cache in a single shot.
Open Outlook 2010, select the Options from File menu then click on Mail and scroll to search for Empty Auto-Complete List button and click.