mail won't open jpeg attachments

On my MBP, sometimes I'll get emails with a few jpeg photos attached. It won't open all of them. Sometimes it will let me open and save 3 or 4 of them, but not the rest. Anyone know what's up? Any of the things I've tried (right clicking, clicking Save as, or attemtping to do a drag & drop into iphoto) doesn't work.

thanks so much for your help!