out–box 
/ˈaʊtˌbɑ:ks/ noun plural out–box·es
[
count]
1 US : a box or other container on a desk in which letters, notes, etc., that are being sent from the desk are placed
—called also (Brit) out tray; —
see picture at office;
compare in-box
2 computers : a computer folder that holds e-mail messages you have not yet sent
