Files that are extremely large can be e-mailed.
Color images take up much more space than black and white or grayscale images.
The higher the resolution, the more disk space that is used. The larger the image, the greater the amount of space needed. Before saving the image, crop just the portion that you need. For example, if you have scanned an entire page, but just need the graphic on the bottom half of the page, crop the scanned image to just that portion.