Created attachment 234665 [details]
mbox file of e-mail

I have a specific e-mail here, I saved it as an mbox file and attached it to this report. It displays normally if I read it in Evolution. When I hit the reply button however, almost all the lines are "Preformatted" instead of "Normal" and do not "word wrap", i.e. break the line at the window border. This causes long horizontal scroll bars to appear. This can be seen in the first screenshot.

I decided to look at the source of the message in Evolution. This gave me garbled text (not just the attachment of the message, but also the text of the message itself), as you can see in the second screenshot. However, when I open the saved mbox file in gedit all the text displays normally.