Mail Attachment images
I have seen some attachments show up in mail 10.11 and 10.11.1 as just ? marks. Quick Look, click and space bar thing.. and the proper image shows up. Emails with this problem also will print inconstant. Not all the email prints, Print Preview panel shows a scroll bar, on the side! No problem downloading, double click and the OS knows how to open the files.. Mail just is inconsistent in previewing them.
iMac, OS X El Capitan (10.11.1)