How to automatically attach E-mail, not embed them
You can do this individually by dragging the image(s) in, right clicking on them and clicking "View as Icon". You can select multiple images at once to do this as well. 

If you would like Mail to do this automatically with all attachments, try the following Terminal command:


  defaults write com.apple.mail DisableInlineAttachmentViewing -bool yes


Relaunch Mail for this to take effect.

Hope this helps!