You don't need to do anything
If some fool addresses his email incorrectly, that's his problem, not yours. While it might be polite to let them know, you're equally at liberty to throw the mail away and ignore the problem. Anything about "if you receive this email in error, you must " can be ignored, too - no-one can oblige you to do something simply by sending you an email.
( le brian, Wed 24 Jun 2009, 1:16, Reply)