Okay. understood. Well, you cannot sent that file as attachment directly. However certain document types such as pdf have send email option when you open. Once you open it, and click on File, Send via email , the default email client in windows opens. In your case, the default email client would be apples mail.
Note : Fusion is able to recognize / handle only mailto protocols.
You cannot change the default email program itself to default host app in windows xp.
I recommend you to install email client in windows xp to achieve your needs. You can go for thunderbird which is free app for windows,