I just sent an email using Mail with some small photos attached. I dragged the photos from the Photos app onto the new email. It appeared to send correctly but when I looked in the sent folder it wasn't displaying the photos. The file size count is bizarre (1.2MB of 166KB): and is actually increasing (I have now deleted the email and warned the recipients to delete it) I tried to send the same photos by dragging files from Finder but a similar thing happened - in this case "?" instead of images. Update... a) A recipient has advised me that the images were fine in the email they received from me so the corruption seems to be in my "sent" folder. b) I sent a test email to myself (but another account name) and the JPG displayed in both the sent and inbox folders so this seems to be an intermittent thing.