Yes, it is possible to add either a CC or BCC to every email sent simply by adding an Additional Email Header Field.  To do this, navigate to the Advanced Settings of an email campaign.  Expand open the Additional Email Header Fields section and press + Add Header.  For a CC provide the Name Cc, and for BCC provide the name Bcc.  Within the Value, this should be email address you would like to use.  Now simply press Save Advanced Settings.

A reference of email header fields can be found here.