Here's what I do on my iMac to change the memory size: Open the .jpg photo by double clicking. This should bring it up in the Preview program. Under "File" pull down to "Save As." At the bottom of the window you should see "Quality" with a horizontal scroll bar. Move the tab on the scroll bar toward "Least" and the memory size will be reduced, so it will be small enough to post here.
You can also change the physical size of the photo as described in one of the postings under "Mac users help" in #2 post above.
Last edited by janeknapp; 11-20-2013 at 12:51 PM.