Application: kmail (4.7.0 )
KDE Platform Version: 4.7.00 (4.7.0) "release 6"
Qt Version: 4.7.3
Operating System: Linux 2.6.37.6-0.7-default x86_64
Distribution: "openSUSE 11.4 (x86_64)"

-- Information about the crash:
Updated KDE Repos from 4.6 to 4.7 using SuSE repos. 
After the conversation I cannot work for more that 5mins without a segmentation fault. Kmail2 eats 5,2GB of memory and dies.
Sometimes interrupted by conflict notifications about changed elements that seem to differ only in the SpamAssassin Version.
*sigh*

The crash can be reproduced some of the time.

-- Backtrace:
Application: KMail (kmail), signal: Segmentation fault
[Current thread is 1 (Thread 0x7fdafccf5760 (LWP 16377))]

Thread 2 (Thread 0x7fdae05d8700 (LWP 16579)):
#0  0x00007fdaf7f0938c in pthread_cond_wait@@GLIBC_2.3.2 () from /lib64/libpthread.so.0
#1  0x00007fdaee5851d4 in WTF::TCMalloc_PageHeap::runScavengerThread(void*) () from /usr/lib64/libQtWebKit.so.4
#2  0x00007fdaf7f04a3f in start_thread () from /lib64/libpthread.so.0
#3  0x00007fdafa0d767d in clone () from /lib64/libc.so.6
#4  0x0000000000000000 in ?? ()

Thread 1 (Thread 0x7fdafccf5760 (LWP 16377)):
[KCrash Handler]
#6  0x00007fdafb5abe37 in QByteArray::append (this=0x7fff819cf530, ba=...) at tools/qbytearray.cpp:1587
#7  0x00007fdaf691ae3c in KMime::Content::encodedBody() () from /usr/lib64/libkmime.so.4
#8  0x00007fdaf691b025 in KMime::Content::encodedContent(bool) () from /usr/lib64/libkmime.so.4
#9  0x00007fdaf580dc71 in MailCommon::FilterActionWithCommand::genericProcess(Akonadi::Item const&, bool) const () from /usr/lib64/libmailcommon.so.4
#10 0x00007fdaf582ba24 in MailCommon::MailFilter::execActions(Akonadi::Item const&, bool&) const () from /usr/lib64/libmailcommon.so.4
#11 0x00007fdaf58195e1 in MailCommon::FilterManager::process(Akonadi::Item const&, MailCommon::FilterManager::FilterSet, bool, QString const&) () from /usr/lib64/libmailcommon.so.4
#12 0x00007fdaf581b56d in MailCommon::FilterManager::Private::slotItemsFetchedForFilter(QList<Akonadi::Item> const&) () from /usr/lib64/libmailcommon.so.4
#13 0x00007fdaf581bb72 in MailCommon::FilterManager::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib64/libmailcommon.so.4
#14 0x00007fdafb6a6a5f in QMetaObject::activate (sender=0x1ba0f30, m=<value optimized out>, local_signal_index=<value optimized out>, argv=0x7fff819cfcb0) at kernel/qobject.cpp:3278
#15 0x00007fdaf6570e52 in Akonadi::ItemFetchJob::itemsReceived(QList<Akonadi::Item> const&) () from /usr/lib64/libakonadi-kde.so.4
#16 0x00007fdaf65f644b in Akonadi::ItemFetchJob::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib64/libakonadi-kde.so.4
#17 0x00007fdafb6a6a5f in QMetaObject::activate (sender=0x1ba0f30, m=<value optimized out>, local_signal_index=<value optimized out>, argv=0x7fff819cfdd0) at kernel/qobject.cpp:3278
#18 0x00007fdafc14a5a2 in KJob::result(KJob*) () from /usr/lib64/libkdecore.so.5
#19 0x00007fdafc14a5e0 in KJob::emitResult() () from /usr/lib64/libkdecore.so.5
#20 0x00007fdaf659afcd in Akonadi::Job::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib64/libakonadi-kde.so.4
#21 0x00007fdaf65f6395 in Akonadi::ItemFetchJob::qt_metacall(QMetaObject::Call, int, void**) () from /usr/lib64/libakonadi-kde.so.4
#22 0x00007fdafb6a637a in QObject::event (this=0x1ba0f30, e=<value optimized out>) at kernel/qobject.cpp:1217
#23 0x00007fdafaa5a144 in QApplicationPrivate::notify_helper (this=0x66b9e0, receiver=0x1ba0f30, e=0x1b303b0) at kernel/qapplication.cpp:4462
#24 0x00007fdafaa626fa in QApplication::notify (this=<value optimized out>, receiver=0x1ba0f30, e=0x1b303b0) at kernel/qapplication.cpp:4341
#25 0x00007fdafc726736 in KApplication::notify(QObject*, QEvent*) () from /usr/lib64/libkdeui.so.5
#26 0x00007fdafb69247c in QCoreApplication::notifyInternal (this=0x7fff819d0920, receiver=0x1ba0f30, event=0x1b303b0) at kernel/qcoreapplication.cpp:731
#27 0x00007fdafb695c75 in sendEvent (receiver=0x0, event_type=0, data=0x611fd0) at kernel/qcoreapplication.h:215
#28 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x611fd0) at kernel/qcoreapplication.cpp:1372
#29 0x00007fdafb6bd093 in sendPostedEvents (s=0x66e760) at kernel/qcoreapplication.h:220
#30 postEventSourceDispatch (s=0x66e760) at kernel/qeventdispatcher_glib.cpp:277
#31 0x00007fdaf214dbd3 in g_main_context_dispatch () from /lib64/libglib-2.0.so.0
#32 0x00007fdaf214e3b0 in ?? () from /lib64/libglib-2.0.so.0
#33 0x00007fdaf214e650 in g_main_context_iteration () from /lib64/libglib-2.0.so.0
#34 0x00007fdafb6bd22f in QEventDispatcherGlib::processEvents (this=0x6117e0, flags=<value optimized out>) at kernel/qeventdispatcher_glib.cpp:422
#35 0x00007fdafaaffbae in QGuiEventDispatcherGlib::processEvents (this=<value optimized out>, flags=<value optimized out>) at kernel/qguieventdispatcher_glib.cpp:204
#36 0x00007fdafb6918d2 in QEventLoop::processEvents (this=<value optimized out>, flags=...) at kernel/qeventloop.cpp:149
#37 0x00007fdafb691ae5 in QEventLoop::exec (this=0x7fff819d07e0, flags=...) at kernel/qeventloop.cpp:201
#38 0x00007fdafb695f2b in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1008
#39 0x000000000040316e in main ()

Reported using DrKonqi