are you talking about images downloaded from a digital camera? if yes, you must use the software that comes with the camera. you must RESIZE the pic. i usually resize the pics to about 350 kb when sending otherwise they will be HUGE.
when i bought my digital camera i had SO much trouble figuring this out. they do not tell you how to do this in the manual. i also had trouble finding the pics once i downloaded them. technology manuals leave out a lot of basic info that we must figure out on our own.