Version: 1.10.3 (using 4.1.3 (KDE 4.1.3), Kubuntu packages) Compiler: cc OS: Linux (i686) release 2.6.27-9-generic After setting preferences in Settings => Configure Kmail => Security => Reading to "prefer HTML to plain text," mail is still displayed in plain text.
Please check also the settings for the folder in the main menu folder>prefer HTML It works for me in 4.2.0
Thank you.