Email Event Confirmation Receipts show BCC and CC addresses all on a single TO line

Entering the BCC And CC addresses for Event Registration emails results in all emails being put on the TO line. This is not proper behavior. CC should be on its own line. BCC Shouldn't show up at all on the email, but the BCC should be a receipient. That's what BCC means (blind carbon copy).

I've noticed this bug in versions of CiviCRM as old as 3.3.