I made this file in MTC for size A2 envelope (fits a card 4.25 x 5.5"). It has a scalloped edge on the flap and a window for the address. I did not include the background texture because it is a purchased file from Lettering Delights. This paper (sunshine.jpg) is one of the FREE files that you receive if you sign up for Lettering Delights, from the Banner Day Background Paper set. Be sure to click on the banner to the side (the one with the giraffe on it) to get it!
Download here: http://www.box.net/shared/sl9lneb5sj