*** Bug 174436 has been marked as a duplicate of this bug. ***

Hello,

Thanks for your report. It sounds as if you are able to reproduce the crash. So could you please have a look at http://techbase.kde.org/Development/Tutorials/Debugging/How_to_create_useful_crash_reports, try to install the debugging packages for your distribution and post a more verbose backtrace?

*** This bug has been marked as a duplicate of bug 163712 ***

Applicazione: Kontact (kontact), segnale SIGABRT
[Thread debugging using libthread_db enabled]
[New Thread 0x7f2eff3696f0 (LWP 5502)]
[KCrash handler]
#5  0x00007f2efc9c6fd5 in raise () from /lib/libc.so.6
#6  0x00007f2efc9c8b43 in abort () from /lib/libc.so.6
#7  0x00007f2efdbcb6b5 in qt_message_output () from /usr/lib/libQtCore.so.4
#8  0x00007f2efdbcb7fd in qFatal () from /usr/lib/libQtCore.so.4
#9  0x00007f2eecfdd538 in KMail::MessageProperty::forget (msgBase=0x142d910)
    at /build/buildd/kdepim-4.1.3/kmail/messageproperty.cpp:180
#10 0x00007f2eed037923 in ~KMMsgBase (this=0x157e)
    at /build/buildd/kdepim-4.1.3/kmail/kmmsgbase.cpp:124
#11 0x00007f2eece969a9 in ~KMMessage (this=0x142d910)
    at /build/buildd/kdepim-4.1.3/kmail/kmmessage.cpp:225
#12 0x00007f2eed03fce2 in KMMsgList::clear (this=0xcaffc8, doDelete=true, 
    syncDict=false) at /build/buildd/kdepim-4.1.3/kmail/kmmsglist.cpp:37
#13 0x00007f2eed0ab2aa in KMFolderMaildir::close (this=0xcaff50, 
    aForced=<value optimized out>)
    at /build/buildd/kdepim-4.1.3/kmail/kmfoldermaildir.cpp:216
#14 0x00007f2eecfa78bc in ~KMFolder (this=0xcae060)
    at /build/buildd/kdepim-4.1.3/kmail/kmfolder.cpp:156
#15 0x00007f2eecff467e in qDeleteAll<QList<KMFolderNode*>::iterator> (begin=
      {i = 0x7fff073ae620}, end={i = 0x157e})
    at /usr/include/qt4/QtCore/qalgorithms.h:346
#16 0x00007f2eecff1dfa in ~KMFolderDir (this=0xc9a8d0)
    at /build/buildd/kdepim-4.1.3/kmail/kmfolderdir.cpp:91
#17 0x00007f2eecff467e in qDeleteAll<QList<KMFolderNode*>::iterator> (begin=
      {i = 0x7fff073ae680}, end={i = 0x157e})
    at /usr/include/qt4/QtCore/qalgorithms.h:346
#18 0x00007f2eecff1dfa in ~KMFolderDir (this=0xc85df0)
    at /build/buildd/kdepim-4.1.3/kmail/kmfolderdir.cpp:91
#19 0x00007f2eecff467e in qDeleteAll<QList<KMFolderNode*>::iterator> (begin=
      {i = 0x7fff073ae6e0}, end={i = 0x157e})
    at /usr/include/qt4/QtCore/qalgorithms.h:346
#20 0x00007f2eecff266d in ~KMFolderRootDir (this=0xc5d498)
    at /build/buildd/kdepim-4.1.3/kmail/kmfolderdir.cpp:37
#21 0x00007f2eecff6042 in ~KMFolderMgr (this=0xc5d480)
    at /build/buildd/kdepim-4.1.3/kmail/kmfoldermgr.cpp:53
#22 0x00007f2eed0c5e4a in KMKernel::cleanup (this=0xba5610)
    at /build/buildd/kdepim-4.1.3/kmail/kmkernel.cpp:1680
#23 0x00007f2eed7631cc in ~KMailPart (this=0xb20f30)
    at /build/buildd/kdepim-4.1.3/kmail/kmail_part.cpp:138
#24 0x00007f2efef79f1b in ~MainWindow (this=0x7871a0)
    at /build/buildd/kdepim-4.1.3/kontact/src/mainwindow.cpp:252
#25 0x00007f2efdccadc5 in QObject::event () from /usr/lib/libQtCore.so.4
#26 0x00007f2efd22f9f6 in QWidget::event () from /usr/lib/libQtGui.so.4
#27 0x00007f2efd548aab in QMainWindow::event () from /usr/lib/libQtGui.so.4
#28 0x00007f2efe710458 in KXmlGuiWindow::event (this=0x157e, ev=0x157e)
    at /build/buildd/kde4libs-4.1.3/kdeui/xmlgui/kxmlguiwindow.cpp:133
#29 0x00007f2efd1ddc3d in QApplicationPrivate::notify_helper ()
   from /usr/lib/libQtGui.so.4
#30 0x00007f2efd1e59ea in QApplication::notify () from /usr/lib/libQtGui.so.4
#31 0x00007f2efe617fcb in KApplication::notify (this=0x7fff073af550, 
    receiver=0x7871a0, event=0x13c9520)
    at /build/buildd/kde4libs-4.1.3/kdeui/kernel/kapplication.cpp:311
#32 0x00007f2efdcbbd61 in QCoreApplication::notifyInternal ()
   from /usr/lib/libQtCore.so.4
#33 0x00007f2efdcbc9fa in QCoreApplicationPrivate::sendPostedEvents ()
   from /usr/lib/libQtCore.so.4
#34 0x00007f2efdce44d3 in ?? () from /usr/lib/libQtCore.so.4
#35 0x00007f2ef8458d3b in g_main_context_dispatch ()
   from /usr/lib/libglib-2.0.so.0
#36 0x00007f2ef845c50d in ?? () from /usr/lib/libglib-2.0.so.0
#37 0x00007f2ef845c6cb in g_main_context_iteration ()
   from /usr/lib/libglib-2.0.so.0
#38 0x00007f2efdce415f in QEventDispatcherGlib::processEvents ()
   from /usr/lib/libQtCore.so.4
#39 0x00007f2efd26fa9f in ?? () from /usr/lib/libQtGui.so.4
#40 0x00007f2efdcba682 in QEventLoop::processEvents ()
   from /usr/lib/libQtCore.so.4
#41 0x00007f2efdcba80d in QEventLoop::exec () from /usr/lib/libQtCore.so.4
#42 0x00007f2efdcbccbd in QCoreApplication::exec ()
   from /usr/lib/libQtCore.so.4
#43 0x00000000004048e5 in main (argc=1, argv=0x7fff073afc38)
    at /build/buildd/kdepim-4.1.3/kontact/src/main.cpp:218
#0  0x00007f2efca3c5f0 in __nanosleep_nocancel () from /lib/libc.so.6

It's not a duplicate of #163712 IMHO

Confirming the same bug - I think. Feel free to delete this if not needed.
Application:
kmail:
  Installed: 4:4.1.2-0ubuntu2
  Candidate: 4:4.1.2-0ubuntu2
  Version table:
 *** 4:4.1.2-0ubuntu2 0
        500 http://archive.ubuntu.com intrepid/main Packages
        100 /var/lib/dpkg/status
OS:
Ubuntu 8.10

Backtrace:
Application: KMail (kmail), signal SIGABRT
(no debugging symbols found)
(no debugging symbols found)
(no debugging symbols found)
[Thread debugging using libthread_db enabled]
[New Thread 0xb41c76c0 (LWP 8819)]
[KCrash handler]
#6  0xb7fec430 in __kernel_vsyscall ()
#7  0xb6447880 in raise () from /lib/tls/i686/cmov/libc.so.6
#8  0xb6449248 in abort () from /lib/tls/i686/cmov/libc.so.6
#9  0xb6fca795 in qt_message_output () from /usr/lib/libQtCore.so.4
#10 0xb6fca872 in qFatal () from /usr/lib/libQtCore.so.4
#11 0xb6fca915 in qt_assert () from /usr/lib/libQtCore.so.4
#12 0xb7ad252d in ?? () from /usr/lib/libkmailprivate.so.4
#13 0xb7a4e52e in KMail::AccountManager::~AccountManager ()
   from /usr/lib/libkmailprivate.so.4
#14 0xb7b3e11e in KMKernel::cleanup () from /usr/lib/libkmailprivate.so.4
#15 0x0804a6ca in _start ()
#0  0xb7fec430 in __kernel_vsyscall ()

*** This bug has been marked as a duplicate of bug 171062 ***