If you put content which could be in the body of the email in an attachment you are saying:
- you don't care about the extra time and effort involved in viewing the message.
- your time is more important than that of the person receiveing the message.
- you don't consider people who view emails through a browser. (Not every web based email client can display attahcments, even PDFs)
- you don't care about the users bandwidth or the time it takes to download the message. (Not everyone has broadband)