You can send stamps, envelopes, pics and paper...there is a limit to total number of each that they can have, also you can only send 15 other's" total at a time (ie. you can write him a 6 page letter front and back and send 5 pictures and 5 envelopes and 5 pieces of blank paper) When I send stamps, I put them on the envelopes and put his name and DC# in the return address spot (I am do not trust th