A lot of emails contain attachments. Sometimes you want to reply to an email vs forward to confirm reciept, for example, but also need to add a couple of more people to the email. Currently if you reply, the original attachment would not attach in the reply. You would need to forward the email, but in that instance need to type in everyones emails again, or you would have needed to save the original attachment, then hit reply, attach it, add the additional email addresses and then send the email. Both options here are less than efficient. But allowing a reply with original attachment option you are making the work flow so much simpler and easier!