Trying to display the attached message immediately crashes kMail. Reading or even answering this message is impossible. Reproducible: Always
Created attachment 101175 [details] Message which immediately crashes kMail if viewed.
Created attachment 101196 [details] Backtrace for kmail2-5.3.1 Backtrace when opening the attached mail with kmail2-5.3.1 -> crash in MimeTreeParser::{parseObjectTree -> toplevelTextNode -> toplevelTextNode}
*** This bug has been marked as a duplicate of bug 368766 ***