Including a Message in a Reply

  Choose Reply Using This Message from the Read pop-up
  menu to display the current message in a Create-Send
  window.  Mail enters some of the address information in the
  Create-Send window.

  In the To entry box, Mail inserts the name of the sender of
  the original message.  In the Subject entry box Mail inserts
  RE: followed by the subject of the original message.

  Edit the text of the original message, if desired, and enter
  the text of your message.  Click on the Send button when the
  message is complete.

  Additional topics:

  *   Using a Create-Send Window