Using either the attach file from the message window or the right click and send to method on pic in filing system (which has the advantage of allowing resize), brings up an error message that says a Microsoft ID sign in is required. It is worth noting that Pics are stored in filing system Picture folder and not being sourced from photo app on Windows 8 machine.
I read previous threads on topic that suggested problem only existed for Send to method and that deleting outbox message and starting again was solution. I found that if I opened message from outbox and sent it again that it went. Still seems that what was a simple process in earlier OS's has been made problematic in Windows 8 and I can't help wondering if a fix for the problem has been devised for people who want to stick with desktop email clients and not bother with MS ID sign ins?