Very Computer

I am getting an undeliverable message when replying to messages that
were created by certain people in my organization.  These people had a
delegate in their delegates list who's account has been removed.  The
delegate was set up to receive a copy of all mail sent to that
particular person, etc.  The delegate has been removed from the list but
only AFTER the account was deleted.  I cannot get these undeliverables
to stop.  HELP!! What do I need to do?