I haven't really used it myself apart from testing. However, tick the box "Rich text" and then the icon "Insert a picture" and select "Add wallpaper". Add the image you want to use as a background wallpaper. Of course any message formatting and the sending of formatted messages should not be disabled under Tools-> Options - Message formatting.
Does it do the trick for you?
Cheers
Thomas

Hi,

If this appears twice my apologies... first submission no response.... First thanks for 11 years of pegasus - amazing.

Please can someone tell me if you can change the background paper (colour/pattern) that the email is written on... for example I want to put a graphpaper effect behind my mail? How can I do this? Thanks in anticipation. Timi. South Africa.