The Band does not have the communication connections (notifications, email, text) via computers, including PCs and Macs. The communications functions are only available via the smartphone app, and only via Bluetooth. Bluetooth connectivity to the Band is not available on PCs and Macs.
Connection via USB does sync the recorded metrics (exercise, heart rate, etc.), but not the communications functions. Microsoft plans to add this functionality, which will be quite a feat, considering the hurdles to overcome getting access to OS X and Windows APIs to access email notifications, messaging, etc.