The 'Replying' option allows you to select whether you want the original senders message included with your reply to his message.
Click the 'Replying' combo-box to view the options associated with it. There are two options listed which are:
Include original message in reply- Select this option and click the 'Update Information' button. This action will allow you to reply to any email you receive with the original sender's message. The original message will be displayed under your reply to the recipient to the email.
'Don't include original message in reply': Selecting this option sends only your message to the recipient of the email. In case you are replying to any particular message the original message is not included as a part of your message