FYI:
For those that may not know …
do your render or screen capture >
open the image in Ps, Ai, etc >
File > Save for Web and Devices >
choose your format … JPG, etc >
choose your quality … low- high quality, etc >
look at the file size (usually in the lower left hand corner) change as you choose output.
As long as your attachment is under 100kb it will upload and give those you are asking
for assistance something larger than a postage stamp size image to reference.
Hope this helps 