Emails with an iPod Touch.

Hi everyone.

My girlfriend just bought an iPod Touch and wants to be able to send me emails on my computer (a Sony VAIO). So I registered an Apple ID because she first recieved a response saying she couldn't send me emails because my adress wasn't an Apple ID. But she still can't, and I can't find any answer why. Is it because I don't use a MacBook or an iMac ? Help us please !!! (I apologize for the mistakes, my native tongue is French)