Create a new email message and select the open separate window icon, , located at the top right corner of the message window. This will open this message as its own window within your browser as show below.
Organize your browser windows so that you can view both your mail folder listing and this message window. Drag the email, from your mail folder list, that you want to include in the message you are composing.
You will now the message you dragged in has been included as an attachment. Enter any other relative information and click the Send button.