What’s your background? you would like to add a watermark to your message which says “confidential” as an extra visual reminder. Whatever it is, I’m sure it’s not just plain white, and the background of your confidential emails doesn’t have to be either. Does Outlook hold such an option?
Add a Background Image to a Message in Outlook 2010:
Click on New to Create a new message
Then select the “Options” tab and now click on the button “Page Color”
Then select the image from location and then click on open and then you have your background image.