I have installed a upvc door that has a glass panel at the bottom and also the top. Is it possible for me to add a letterbox in the plastic bit in between the 2 glass panels?

Raf, February 2009

yes but make sure you buy a letter plate that fits in the mid-rail.
they come in different sizes ie thickness for a mid rail and thickness for a panel
ask the retailer they will know (go to a window company)
you will need to router out the mid-rail to fit the letter plate; make sure you use the female part for the new hole

tom, February 2009