One of the good things about Mail is that it tries to display files that you attach in the body of your outgoing emails. However, sometimes this drives me nuts. I was composing an email to a cousin of mine and I was attaching two PDF files and sure enough Mail displayed the first PDF file in the body of the message. I didn't want this as it was interfering with what I was typing. So out of frustration I Control-Clicked on the attached PDF and there was an option in the Contextual Menu that popped up that said "view as icon". It did exactly that and I was happy again!