Resizing an image on your Mac is easy-peasy. Find the image in the Finder and Right Click on the file name. From the popup menu that appears, choose Open In Preview. Once opened, go to the Tools menu and select Adjust Size. There are two boxes, one for width and one for height. Type 1280 in whichever box has the largest number and press the Tab key. The other side will adjust automatically. Click in the box called Resolution and change the number to 125 and just make sure that the drop down to the right says Pixels / Inch. Once your entries are complete, click OK and the image is resized. Close Preview. The file is still in the Finder window but is now resized so you can attach it to an email and send it in.
PLEASE NOTE THAT THIS IS AN OLD GRAPHIC. PPI NO LONGER MATTERS AND THE LONG EDGE SHOULD BE 1440 PIXELS