Is it possible to bcc/cc an admin on every system email? My understanding is that the testToEmailAddress config items replaces the to address for system emails.

Is there a way, outside of extending the system functionality with a plugin, to add a to/cc/bcc address for system emails? (Use case: I want to CC/BCC an admin on every system email.)
You can easily do that without any plugin by using a transactional email provider like https://mandrill.com/ or http://sendgrid.com/