From: Alice <alice@example.org>
To: Daniel <daniel@example.org>
Cc: Bob <bob@example.org>
Subject: wowsers!
cc: Charles <charles@example.org>
Message-Id: <multiple-cc@example.org>
Date: Thu, 16 Jun 2016 22:14:41 -0400

Note the Cc: and cc: headers.