Emailing photo from iphone, then open in CS5. I need to change resolution to 300 (per instructions for contest submissions). Instructions say 300ppi, 7inches in width (2100 pixs) should have file 1 MG. My files are about 4-5 MGs. Doesn't seem to matter if I send the image medium, large or actual size. Still comes out way over 1 MG. What am I doing wrong?