If you are getting graphic boxes then it seems like you are using something like, Edit > Select all, then Edit > Copy.
If so, try dragging your mouse across the text you want to copy, then whilst the text is highlighted and with the mouse cursor resting over the highlight, right click the mouse and select Copy.
Then Paste that into your text editor.
No matter what word processor or text program I use, if I want to copy and paste some of the text in an email I receive, I cannot get the text to copy. What I get is a "graphic" box or picture box with nothing in it. I use Yahoo mail to get my emails exclusively. I have even tried to copy it into a HTML program with no better results.........
How can I copy portions of text from an email?