There are (received) emails consisting of text plus graphics. If I SELECT ALL and paste into WORD, the text appears, but only rectangles for the graphics. Whether or not I can paste individual graphics into the rectangles, is variable, but usually not. Then paradoxically, there are emails where I can paste graphics from a received into a new email ONLY after pasting first into WORD, then recopying from Word.
I think it gets more complicated than even that - that is why I listed 'complex' along with 'paradoxical' and that is where I have to owe you further 'detail'.