Class for SMTP

This is a class for SMTP. SMTP is use for sending mail. I have write it into a class for easily of use. It also support of multi-receiver, which mean can send an email to more than one poeple in once time. It is more like a learning version then application. But it can be use in any application. I have include a demo to teach how to send an email. There will be 3 steps to send email. Every code is in comment.