Does your image viewing software allow you to resize and save files at different levels of compression?
If not, download irfanview - just google it. It's a good and straightforward piece of image viewing and handling software. Look under "Image" "Resize/resample" to set to about 800x600 pixels, then do "Save as..." and up will come a box allowing you to adjust the compression (change the %). Then see what size the resulting file is. You are looking for a jpeg under 200k to attach here.
Good luck! Eric.