I often embed screenshots or paste Excel tables as pictures (Windows Metafile) into my messages and they look good when composing.

However, when the messages are being received, Outlook automatically resizes these images based upon the width of the Reading Pane making them impossible to read without opening the message and/or resize message window (which not everyone is aware of).

How can I prevent Outlook from automatically resize these images and force it to always display it in full size?