Posted to Google Sites
Step 1: Open your image in the image library.
Step 2: Open in the Email app, not Gmail.
Step 3: Choose the “Resize Image” option. Notice that the original image, in this example, is 4.4 MB (rather large).
Step 4: Resize the image to 10% of its original.
Voilà! You can see the new image is 1/10 the original size.