Version: 1.13.1 (using 4.4.1 (KDE 4.4.1) "release 225", KDE:KDE4:Factory:Desktop / openSUSE_11.2) Compiler: gcc OS: Linux (i686) release 2.6.33-0.1-default Since I've upgraded to KDE SC 4.4.0, some icons in Kmail toolbar don't appear. Two icons that don't appear in toolbar are "Mark thread as read" and "Mark message as read", even though they are listed on the right-hand side in toolbar configuration dialog. Nothing changes if I remove those two icons and put them back again.
Thank you for taking the time to file a bug report. KMail2 was released in 2011, and the entire code base went through significant changes. We are currently in the process of porting to Qt5 and KF5. It is unlikely that these bugs are still valid in KMail2. We welcome you to try out KMail 2 with the KDE 4.14 release and give your feedback.