If you could attach one of the mail (in mbox format) that would be nice, but as you have privacy issues you can try and replace the text with bogus text and see if that still produces the error (the actual text should not matter) and attach that mail.

Else try and attach gdb to kmail when you have one of these freezes and post a full backtrace for all threads.

Hi, unfortunately replacing the private stuff ist very difficult, because the mail ist just very, very long. If there was a script somewhere which did this automatically?
I have tried with gdb, which did not went very well. I do not why. I just copied instructions someone gave me on another report.
But somehow after doing this, running Kmail without gdb again, the crash occured again, but somehow Kmail managed to start gdb this time. Both things I attach.

Application: KMail (kmail), signal: Aborted
[Current thread is 1 (Thread 0xb2a6a730 (LWP 23155))]

Thread 3 (Thread 0xafb30b70 (LWP 23165)):
#0  0xb7fe1424 in __kernel_vsyscall ()
#1  0xb622d4dc in pthread_cond_wait@@GLIBC_2.3.2 () from /lib/libpthread.so.0
#2  0xb67b7d9d in pthread_cond_wait () from /lib/libc.so.6
#3  0xb45f13a5 in WTF::TCMalloc_PageHeap::scavengerThread (this=0xb4af4680) at wtf/FastMalloc.cpp:2378
#4  0xb45f1481 in WTF::TCMalloc_PageHeap::runScavengerThread (context=0xb4af4680) at wtf/FastMalloc.cpp:1497
#5  0xb6228cc9 in start_thread () from /lib/libpthread.so.0
#6  0xb67aa69e in clone () from /lib/libc.so.6

Thread 2 (Thread 0xad975b70 (LWP 23168)):
#0  0xb4f14e36 in clock_gettime () from /lib/librt.so.1
#1  0xb69fc50b in do_gettime () at tools/qelapsedtimer_unix.cpp:105
#2  qt_gettime () at tools/qelapsedtimer_unix.cpp:119
#3  0xb6ad36e5 in QTimerInfoList::updateCurrentTime (this=0x8bbb864) at kernel/qeventdispatcher_unix.cpp:339
#4  0xb6ad372a in QTimerInfoList::timerWait (this=0x8bbb864, tm=...) at kernel/qeventdispatcher_unix.cpp:442
#5  0xb6ad17a8 in timerSourcePrepareHelper (src=<value optimized out>, timeout=0xad97509c) at kernel/qeventdispatcher_glib.cpp:136
#6  0xb6ad183d in timerSourcePrepare (source=0x0, timeout=0xb4f18ff4) at kernel/qeventdispatcher_glib.cpp:169
#7  0xb5054e6a in g_main_context_prepare () from /lib/libglib-2.0.so.0
#8  0xb5055279 in ?? () from /lib/libglib-2.0.so.0
#9  0xb5055848 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#10 0xb6ad159f in QEventDispatcherGlib::processEvents (this=0x869e948, flags=...) at kernel/qeventdispatcher_glib.cpp:417
#11 0xb6aa1609 in QEventLoop::processEvents (this=0xad975270, flags=) at kernel/qeventloop.cpp:149
#12 0xb6aa1a8a in QEventLoop::exec (this=0xad975270, flags=...) at kernel/qeventloop.cpp:201
#13 0xb699db7e in QThread::exec (this=0x8a0e1e8) at thread/qthread.cpp:490
#14 0xb6a8035b in QInotifyFileSystemWatcherEngine::run (this=0x8a0e1e8) at io/qfilesystemwatcher_inotify.cpp:248
#15 0xb69a0df9 in QThreadPrivate::start (arg=0x8a0e1e8) at thread/qthread_unix.cpp:266
#16 0xb6228cc9 in start_thread () from /lib/libpthread.so.0
#17 0xb67aa69e in clone () from /lib/libc.so.6

Thread 1 (Thread 0xb2a6a730 (LWP 23155)):
[KCrash Handler]
#7  0xb7fe1424 in __kernel_vsyscall ()
#8  0xb6704941 in raise () from /lib/libc.so.6
#9  0xb6707e42 in abort () from /lib/libc.so.6
#10 0xb6902055 in __gnu_cxx::__verbose_terminate_handler() () from /usr/lib/libstdc++.so.6
#11 0xb68fff35 in ?? () from /usr/lib/libstdc++.so.6
#12 0xb68fff72 in std::terminate() () from /usr/lib/libstdc++.so.6
#13 0xb69000e1 in __cxa_throw () from /usr/lib/libstdc++.so.6
#14 0xb6996ea5 in qBadAlloc () at global/qglobal.cpp:1996
#15 0xb69ec895 in q_check_ptr<void> (this=0xbfffd634, alloc=1073741823) at ../../include/QtCore/../../src/corelib/global/qglobal.h:1708
#16 QString::realloc (this=0xbfffd634, alloc=1073741823) at tools/qstring.cpp:1285
#17 0xb69ecd27 in QString::append (this=0xbfffd634, str=...) at tools/qstring.cpp:1500
#18 0xb54f8431 in operator+= (wrappedText=..., indent=..., maxLength=<value optimized out>) at /usr/include/qt4/QtCore/qstring.h:281
#19 KPIMTextEdit::TextUtils::flowText (wrappedText=..., indent=..., maxLength=<value optimized out>) at ../../kpimtextedit/textutils.cpp:156
#20 0xb5c4de01 in MessageCore::StringUtil::flushPart (msg=<value optimized out>, textParts=<value optimized out>, indent=..., maxLength=38) at ../../messagecore/stringutil.cpp:158
#21 0xb5c51da9 in MessageCore::StringUtil::smartQuote (msg=..., maxLineLength=76) at ../../messagecore/stringutil.cpp:897
#22 0xb593fe51 in TemplateParser::TemplateParser::asQuotedString (this=0xbfffe2e4, msg=..., aIndentStr=..., selection=..., aStripSignature=true, allowDecryption=true) at ../../templateparser/templateparser.cpp:1444
#23 0xb5943d08 in TemplateParser::TemplateParser::processWithTemplate (this=0xbfffe2e4, tmpl=...) at ../../templateparser/templateparser.cpp:393
#24 0xb593f021 in TemplateParser::TemplateParser::process (this=0xbfffe2e4, aorig_msg=..., afolder=...) at ../../templateparser/templateparser.cpp:271
#25 0xb5b9c38c in MessageComposer::MessageFactory::createReply (this=0xbfffe560) at ../../messagecomposer/messagefactory.cpp:317
#26 0xb77a248c in KMReplyToCommand::execute (this=0xab1c7a8) at ../../kmail/kmcommands.cpp:825
#27 0xb779b8e0 in KMCommand::slotPostTransfer (this=0xab1c7a8, result=KMCommand::OK) at ../../kmail/kmcommands.cpp:269
#28 0xb77a072f in KMCommand::qt_metacall (this=0xab1c7a8, _c=QMetaObject::InvokeMetaMethod, _id=7, _a=0xbfffe768) at ./kmcommands.moc:88
#29 0xb77a0d42 in KMReplyToCommand::qt_metacall (this=0xab1c7a8, _c=QMetaObject::InvokeMetaMethod, _id=7, _a=0xbfffe768) at ./kmcommands.moc:680
#30 0xb6aa88ca in QMetaObject::metacall (object=0xab1c7a8, cl=23155, idx=7, argv=0xbfffe768) at kernel/qmetaobject.cpp:237
#31 0xb6abb6ad in QMetaObject::activate (sender=0xab1c7a8, m=0xb7903840, local_signal_index=0, argv=0x0) at kernel/qobject.cpp:3280
#32 0xb779a3f3 in KMCommand::messagesTransfered (this=0xab1c7a8, _t1=KMCommand::OK) at ./kmcommands.moc:103
#33 0xb779fc7c in KMCommand::slotJobFinished (this=0xab1c7a8) at ../../kmail/kmcommands.cpp:379
#34 0xb77a06f3 in KMCommand::qt_metacall (this=0xab1c7a8, _c=QMetaObject::InvokeMetaMethod, _id=9, _a=0xbfffe918) at ./kmcommands.moc:90
#35 0xb77a0d42 in KMReplyToCommand::qt_metacall (this=0xab1c7a8, _c=QMetaObject::InvokeMetaMethod, _id=9, _a=0xbfffe918) at ./kmcommands.moc:680
#36 0xb6aa88ca in QMetaObject::metacall (object=0xab1c7a8, cl=23155, idx=9, argv=0xbfffe918) at kernel/qmetaobject.cpp:237
#37 0xb6abb6ad in QMetaObject::activate (sender=0xa8b2460, m=0xb7bbe548, local_signal_index=3, argv=0x0) at kernel/qobject.cpp:3280
#38 0xb7a3cd83 in KJob::result (this=0xa8b2460, _t1=0xa8b2460) at ./kjob.moc:194
#39 0xb7a3d0e8 in KJob::emitResult (this=0xa8b2460) at ../../kdecore/jobs/kjob.cpp:312
#40 0xb5dc76f9 in delayedEmitResult (this=0xa8b2460, _c=QMetaObject::InvokeMetaMethod, _id=34, _a=0xa4b95e8) at ../../akonadi/job.cpp:144
#41 Akonadi::Job::qt_metacall (this=0xa8b2460, _c=QMetaObject::InvokeMetaMethod, _id=34, _a=0xa4b95e8) at ./job.moc:91
#42 0xb5db2f8a in Akonadi::ItemFetchJob::qt_metacall (this=0xa8b2460, _c=QMetaObject::InvokeMetaMethod, _id=34, _a=0xa4b95e8) at ./itemfetchjob.moc:73
#43 0xb6aa88ca in QMetaObject::metacall (object=0xa8b2460, cl=23155, idx=34, argv=0xa4b95e8) at kernel/qmetaobject.cpp:237
#44 0xb6ab3df6 in QMetaCallEvent::placeMetaCall (this=0xaa32510, object=0xa8b2460) at kernel/qobject.cpp:534
#45 0xb6ab56a2 in QObject::event (this=0xa8b2460, e=0x6) at kernel/qobject.cpp:1219
#46 0xb6d02fdc in QApplicationPrivate::notify_helper (this=0x8089890, receiver=0xa8b2460, e=0xaa32510) at kernel/qapplication.cpp:4396
#47 0xb6d0904e in QApplication::notify (this=0xbffff2ac, receiver=0xa8b2460, e=0xaa32510) at kernel/qapplication.cpp:3798
#48 0xb7dd0f8a in KApplication::notify (this=0xbffff2ac, receiver=0xa8b2460, event=0xaa32510) at ../../kdeui/kernel/kapplication.cpp:311
#49 0xb6aa2b3b in QCoreApplication::notifyInternal (this=0xbffff2ac, receiver=0xa8b2460, event=0xaa32510) at kernel/qcoreapplication.cpp:732
#50 0xb6aa5d8b in sendEvent (receiver=0x0, event_type=0, data=0x80543c0) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:215
#51 QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x80543c0) at kernel/qcoreapplication.cpp:1373
#52 0xb6aa5f4d in QCoreApplication::sendPostedEvents (receiver=0x0, event_type=0) at kernel/qcoreapplication.cpp:1266
#53 0xb6ad1a74 in sendPostedEvents (s=0x808bb20) at ../../include/QtCore/../../src/corelib/kernel/qcoreapplication.h:220
#54 postEventSourceDispatch (s=0x808bb20) at kernel/qeventdispatcher_glib.cpp:277
#55 0xb5051855 in g_main_context_dispatch () from /lib/libglib-2.0.so.0
#56 0xb5055668 in ?? () from /lib/libglib-2.0.so.0
#57 0xb5055848 in g_main_context_iteration () from /lib/libglib-2.0.so.0
#58 0xb6ad1565 in QEventDispatcherGlib::processEvents (this=0x807e0d0, flags=...) at kernel/qeventdispatcher_glib.cpp:415
#59 0xb6dc4be5 in QGuiEventDispatcherGlib::processEvents (this=0x807e0d0, flags=...) at kernel/qguieventdispatcher_glib.cpp:204
#60 0xb6aa1609 in QEventLoop::processEvents (this=0xbffff1c4, flags=) at kernel/qeventloop.cpp:149
#61 0xb6aa1a8a in QEventLoop::exec (this=0xbffff1c4, flags=...) at kernel/qeventloop.cpp:201
#62 0xb6aa600f in QCoreApplication::exec () at kernel/qcoreapplication.cpp:1009
#63 0xb6d01e07 in QApplication::exec () at kernel/qapplication.cpp:3672
#64 0x0804a4e6 in main (argc=1, argv=0xbffff464) at ../../kmail/main.cpp:145

gdb kmail
GNU gdb (GDB) 7.2-ubuntu
Copyright (C) 2010 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
and "show warranty" for details.
This GDB was configured as "i686-linux-gnu".
For bug reporting instructions, please see:
<http://www.gnu.org/software/gdb/bugs/>...
Reading symbols from /usr/bin/kmail...Reading symbols from /usr/lib/debug/usr/bin/kmail...done.
done.
(gdb) run
Starting program: /usr/bin/kmail 
[Thread debugging using libthread_db enabled]

Program exited normally.
(gdb) QInotifyFileSystemWatcherEngine::addPaths: inotify_add_watch failed: Datei oder Verzeichnis nicht gefunden
QFileSystemWatcher: failed to add paths: /home/mark/.config/ibus/bus
Bus::open: Can not get ibus-daemon's address. 
IBusInputContext::createInputContext: no connection to ibus-daemon 
^CQuit
(gdb) bt+
Undefined command: "bt+".  Try "help".
(gdb) Enchant dict for "de" 0x9ff7fb0 
^CQuit
(gdb) bt
No stack.
(gdb) bt
No stack.
(gdb) bt
No stack.
(gdb) c
The program is not being run.
(gdb) terminate called after throwing an instance of 'std::bad_alloc'
  what():  std::bad_alloc
*** KMail got signal 6 (Exiting)
*** Dead letters dumped.
QSocketNotifier: Invalid socket 17 and type 'Read', disabling...
KCrash: Application 'kmail' crashing...
KCrash: Attempting to start /usr/lib/kde4/libexec/drkonqi from kdeinit
sock_file=/home/mark/.kde/socket-linus/kdeinit4__0
^CQuit

(In reply to comment #4)
* gdb kmail
* run --nofork
(kmail and most kde applications fork on start)
* threads apply all bt full

But the backtrace you posted showed where the code crashed, I just can't figure out why :(

*** Bug 262072 has been marked as a duplicate of this bug. ***

*** Bug 263584 has been marked as a duplicate of this bug. ***

Created attachment 56328 [details]
sample message that prompted crash on reply

While I'm not entirely sure that the bug that I reported is actually a duplicate of this one, I've attached a sample message that prompts a crash.  For me, this message caused a complete crash *EVERY* time that I tried to reply.  I do not observe the problem that this bug seems to indicate - that is, I have no problem *viewing* the email, only 'reply'ing to it.

(In reply to comment #8)
> Created an attachment (id=56328) [details]
> sample message that prompted crash on reply
> 
[cut]
> I have no problem *viewing* the email, only 'reply'ing to it.

I can't reproduce the crash with this email. However, it shows a curious issue when answering, the 4th line in the quoted signature isn't displayed correctly (the one with the fax number)

Is this still present with a resent version?

I can not tell, I have given up testing after a month intensive testing, since there was a low response rate on bug reports, no new beta (I am also not aware of a new beta, at least for Kubuntu) and with so many bugs, Kmail was not very much fun.

Closing due to lack of reproducibility.