After observing regular crashes in KMail when moving mails between folders (via context menu, then "Move to", on mail in list of mails), I ran kmail via gdb with debuginfod enabled.
Akonadi is no affected by crash, I still get popups on incoming mails even after KMail had crashed.

Version numbers of concerned programs/libraries:
KMail 22.12.3, Fedora release 1.fc37
QWayand 5.15.8, Fedora release 1.fc37
KF5 KXmlGui 5.103.0, Fedora release 1.fc37

Most recent output in terminal before crash:

qt.qpa.wayland: Creating a fake screen in order for Qt not to crash
kf.notifications: env says KDE is running but SNI unavailable -- check KDE_FULL_SESSION and XDG_CURRENT_DESKTOP
"Object does not exist at path “/org/freedesktop/NetworkManager/ActiveConnection/6”"
"Object does not exist at path “/org/freedesktop/NetworkManager/ActiveConnection/5”"
[Thread 0x7fff75bfb6c0 (LWP 9496) exited]
kf.notifications: env says KDE is running but SNI unavailable -- check KDE_FULL_SESSION and XDG_CURRENT_DESKTOP
[Thread 0x7fff773fe6c0 (LWP 9633) exited]
[Thread 0x7fff753fa6c0 (LWP 8215) exited]
qt.qpa.wayland: setGrabPopup called with a parent, QtWaylandClient::QWaylandXdgSurface(0x555556dff750) which does not match the current topmost grabbing popup, QtWaylandClient::QWaylandXdgSurface(0x5555571e1880) According to the xdg-shell protocol, this is not allowed. The wayland QPA plugin is currently handling it by setting the parent to the topmost grabbing popup. Note, however, that this may cause positioning errors and popups closing unxpectedly because xdg-shell mandate that child popups close before parents
qt.qpa.wayland: setGrabPopup called with a parent, QtWaylandClient::QWaylandXdgSurface(0x555556dff750) which does not match the current topmost grabbing popup, QtWaylandClient::QWaylandXdgSurface(0x5555571e1880) According to the xdg-shell protocol, this is not allowed. The wayland QPA plugin is currently handling it by setting the parent to the topmost grabbing popup. Note, however, that this may cause positioning errors and popups closing unxpectedly because xdg-shell mandate that child popups close before parents
qt.qpa.wayland: setGrabPopup called with a parent, QtWaylandClient::QWaylandXdgSurface(0x555556dff750) which does not match the current topmost grabbing popup, QtWaylandClient::QWaylandXdgSurface(0x5555571e1880) According to the xdg-shell protocol, this is not allowed. The wayland QPA plugin is currently handling it by setting the parent to the topmost grabbing popup. Note, however, that this may cause positioning errors and popups closing unxpectedly because xdg-shell mandate that child popups close before parents
qt.qpa.wayland: setGrabPopup called with a parent, QtWaylandClient::QWaylandXdgSurface(0x555556dff750) which does not match the current topmost grabbing popup, QtWaylandClient::QWaylandXdgSurface(0x7fff6c0678b0) According to the xdg-shell protocol, this is not allowed. The wayland QPA plugin is currently handling it by setting the parent to the topmost grabbing popup. Note, however, that this may cause positioning errors and popups closing unxpectedly because xdg-shell mandate that child popups close before parents
qt.qpa.wayland: setGrabPopup called with a parent, QtWaylandClient::QWaylandXdgSurface(0x555556dff750) which does not match the current topmost grabbing popup, QtWaylandClient::QWaylandXdgSurface(0x7fff6c0678b0) According to the xdg-shell protocol, this is not allowed. The wayland QPA plugin is currently handling it by setting the parent to the topmost grabbing popup. Note, however, that this may cause positioning errors and popups closing unxpectedly because xdg-shell mandate that child popups close before parents
qt.qpa.wayland: setGrabPopup called with a parent, QtWaylandClient::QWaylandXdgSurface(0x555556dff750) which does not match the current topmost grabbing popup, QtWaylandClient::QWaylandXdgSurface(0x5555571e7000) According to the xdg-shell protocol, this is not allowed. The wayland QPA plugin is currently handling it by setting the parent to the topmost grabbing popup. Note, however, that this may cause positioning errors and popups closing unxpectedly because xdg-shell mandate that child popups close before parents
[New Thread 0x7fff753fa6c0 (LWP 11224)]
[New Thread 0x7fff773fe6c0 (LWP 11225)]
[New Thread 0x7fff75bfb6c0 (LWP 11226)]
[New Thread 0x7ffeecbfc6c0 (LWP 11326)]
[New Thread 0x7ffeebbfa6c0 (LWP 11328)]
[New Thread 0x7ffeec3fb6c0 (LWP 11327)]
[New Thread 0x7ffeeb3f96c0 (LWP 11329)]
[New Thread 0x7ffeeabf86c0 (LWP 11331)]
[New Thread 0x7fff135ff6c0 (LWP 11345)]
[Thread 0x7ffeeabf86c0 (LWP 11331) exited]
[Thread 0x7fff135ff6c0 (LWP 11345) exited]
org.kde.pim.ldapclient: We have an error during reading password  "Entry not found"
[Thread 0x7fff773fe6c0 (LWP 11225) exited]
[Thread 0x7ffeebbfa6c0 (LWP 11328) exited]
[Thread 0x7ffeecbfc6c0 (LWP 11326) exited]
[Thread 0x7ffeec3fb6c0 (LWP 11327) exited]
[Thread 0x7fff75bfb6c0 (LWP 11226) exited]
[Thread 0x7fff753fa6c0 (LWP 11224) exited]
[New Thread 0x7fff753fa6c0 (LWP 11424)]
[Detaching after fork from child process 11425]
[Detaching after fork from child process 11427]
[New Thread 0x7fff75bfb6c0 (LWP 11430)]
[Detaching after fork from child process 11431]
[Thread 0x7fff75bfb6c0 (LWP 11430) exited]
qt.qpa.wayland: setGrabPopup called with a parent, QtWaylandClient::QWaylandXdgSurface(0x555556dff750) which does not match the current topmost grabbing popup, QtWaylandClient::QWaylandXdgSurface(0x7fff6c06c240) According to the xdg-shell protocol, this is not allowed. The wayland QPA plugin is currently handling it by setting the parent to the topmost grabbing popup. Note, however, that this may cause positioning errors and popups closing unxpectedly because xdg-shell mandate that child popups close before parents
qt.qpa.wayland: setGrabPopup called with a parent, QtWaylandClient::QWaylandXdgSurface(0x555556dff750) which does not match the current topmost grabbing popup, QtWaylandClient::QWaylandXdgSurface(0x7fff6c06c240) According to the xdg-shell protocol, this is not allowed. The wayland QPA plugin is currently handling it by setting the parent to the topmost grabbing popup. Note, however, that this may cause positioning errors and popups closing unxpectedly because xdg-shell mandate that child popups close before parents
qt.qpa.wayland: setGrabPopup called with a parent, QtWaylandClient::QWaylandXdgSurface(0x555556dff750) which does not match the current topmost grabbing popup, QtWaylandClient::QWaylandXdgSurface(0x555555ae7520) According to the xdg-shell protocol, this is not allowed. The wayland QPA plugin is currently handling it by setting the parent to the topmost grabbing popup. Note, however, that this may cause positioning errors and popups closing unxpectedly because xdg-shell mandate that child popups close before parents
[New Thread 0x7fff75bfb6c0 (LWP 11525)]
[New Thread 0x7ffeec3fb6c0 (LWP 11526)]
[New Thread 0x7ffeecbfc6c0 (LWP 11527)]
[New Thread 0x7fff1343f6c0 (LWP 11530)]
[Thread 0x7fff1343f6c0 (LWP 11530) exited]
[Thread 0x7ffeecbfc6c0 (LWP 11527) exited]
[Thread 0x7ffeec3fb6c0 (LWP 11526) exited]
[Thread 0x7fff75bfb6c0 (LWP 11525) exited]
[New Thread 0x7fff75bfb6c0 (LWP 11561)]
[Thread 0x7fff75bfb6c0 (LWP 11561) exited]
[Detaching after fork from child process 11822]
[Detaching after fork from child process 11824]
[New Thread 0x7fff75bfb6c0 (LWP 11828)]
[Detaching after fork from child process 11829]
[Thread 0x7fff75bfb6c0 (LWP 11828) exited]
qt.qpa.wayland: setGrabPopup called with a parent, QtWaylandClient::QWaylandXdgSurface(0x555556dff750) which does not match the current topmost grabbing popup, QtWaylandClient::QWaylandXdgSurface(0x555557a17df0) According to the xdg-shell protocol, this is not allowed. The wayland QPA plugin is currently handling it by setting the parent to the topmost grabbing popup. Note, however, that this may cause positioning errors and popups closing unxpectedly because xdg-shell mandate that child popups close before parents
qt.qpa.wayland: setGrabPopup called with a parent, QtWaylandClient::QWaylandXdgSurface(0x555556dff750) which does not match the current topmost grabbing popup, QtWaylandClient::QWaylandXdgSurface(0x555557a17df0) According to the xdg-shell protocol, this is not allowed. The wayland QPA plugin is currently handling it by setting the parent to the topmost grabbing popup. Note, however, that this may cause positioning errors and popups closing unxpectedly because xdg-shell mandate that child popups close before parents
qt.qpa.wayland: setGrabPopup called with a parent, QtWaylandClient::QWaylandXdgSurface(0x555556dff750) which does not match the current topmost grabbing popup, QtWaylandClient::QWaylandXdgSurface(0x555556f7e980) According to the xdg-shell protocol, this is not allowed. The wayland QPA plugin is currently handling it by setting the parent to the topmost grabbing popup. Note, however, that this may cause positioning errors and popups closing unxpectedly because xdg-shell mandate that child popups close before parents
malloc(): mismatching next->prev_size (unsorted)

Backtrace as produced by gdb:

Thread 1 "kmail" received signal SIGABRT, Aborted.
__pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44
Downloading source file /usr/src/debug/glibc-2.36-9.fc37.x86_64/nptl/pthread_kill.c
44            return INTERNAL_SYSCALL_ERROR_P (ret) ? INTERNAL_SYSCALL_ERRNO (ret) : 0;
(gdb) bt
#0  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44
#1  0x00007fffee2afec3 in __pthread_kill_internal (signo=6, threadid=<optimized out>) at pthread_kill.c:78
#2  0x00007fffee25fa76 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
#3  0x00007fffee2497fc in __GI_abort () at abort.c:79
#4  0x00007fffee2a408e in __libc_message (action=action@entry=do_abort, fmt=fmt@entry=0x7fffee3bd465 "%s\n") at ../sysdeps/posix/libc_fatal.c:155
#5  0x00007fffee2b9b9c in malloc_printerr (str=str@entry=0x7fffee3c0508 "malloc(): mismatching next->prev_size (unsorted)") at malloc.c:5660
#6  0x00007fffee2bd01c in _int_malloc (av=av@entry=0x7fffee3f6c80 <main_arena>, bytes=bytes@entry=1040) at malloc.c:4003
#7  0x00007fffee2bdded in __GI___libc_malloc (bytes=1040) at malloc.c:3323
#8  0x00007fffee4aec0c in operator new (sz=sz@entry=1040) at ../../../../libstdc++-v3/libsupc++/new_op.cc:50
#9  0x00007fffef1880d2 in QRasterPaintEngine::createState (this=<optimized out>, orig=0x0) at painting/qpaintengine_raster.cpp:632
#10 QRasterPaintEngine::createState (this=<optimized out>, orig=<optimized out>) at painting/qpaintengine_raster.cpp:628
#11 0x00007fffef1a09ca in QPainter::begin (this=0x7fffffffcb98, pd=0x555556a88068) at painting/qpainter.cpp:1785
#12 0x00007fffef1a0c6a in QPainter::QPainter (this=<optimized out>, pd=<optimized out>) at painting/qpainter.cpp:1500
#13 0x00007fffe73c4668 in QtWaylandClient::QWaylandShmBackingStore::beginPaint (region=..., this=0x5555565f4230) at /usr/src/debug/qt5-qtwayland-5.15.8-1.fc37.x86_64/src/client/qwaylandshmbackingstore.cpp:192
#14 QtWaylandClient::QWaylandShmBackingStore::beginPaint (this=this@entry=0x5555565f4230, region=...) at /usr/src/debug/qt5-qtwayland-5.15.8-1.fc37.x86_64/src/client/qwaylandshmbackingstore.cpp:184
#15 0x00007fffef0f1425 in QBackingStore::beginPaint (this=0x555555bedec0, region=...) at painting/qbackingstore.cpp:138
#16 0x00007fffef7bfed5 in QWidgetRepaintManager::paintAndFlush (this=0x5555566b1700) at kernel/qwidgetrepaintmanager.cpp:989
#17 0x00007fffef7f1bf8 in QWidget::event (this=0x555555a75740, event=0x555555981280) at kernel/qwidget.cpp:8990
#18 0x00007fffef5c2d9d in KXmlGuiWindow::event (this=0x555555a75740, ev=0x555555981280) at /usr/src/debug/kf5-kxmlgui-5.103.0-1.fc37.x86_64/src/kxmlguiwindow.cpp:220
#19 0x00007fffef7aed62 in QApplicationPrivate::notify_helper (this=<optimized out>, receiver=0x555555a75740, e=0x555555981280) at kernel/qapplication.cpp:3640
#20 0x00007fffeea9d4e8 in QCoreApplication::notifyInternal2 (receiver=0x555555a75740, event=0x555555981280) at kernel/qcoreapplication.cpp:1064
#21 0x00007fffeea9d6d2 in QCoreApplication::sendEvent (receiver=<optimized out>, event=<optimized out>) at kernel/qcoreapplication.cpp:1462
#22 0x00007fffeeaa0854 in QCoreApplicationPrivate::sendPostedEvents (receiver=0x0, event_type=0, data=0x55555557d3b0) at kernel/qcoreapplication.cpp:1821
#23 0x00007fffeeaa0aec in QCoreApplication::sendPostedEvents (receiver=<optimized out>, event_type=<optimized out>) at kernel/qcoreapplication.cpp:1680
#24 0x00007fffeeaeeb07 in postEventSourceDispatch (s=0x5555555a60a0) at kernel/qeventdispatcher_glib.cpp:277
#25 0x00007fffe844bc7f in g_main_dispatch (context=0x7fffd4005010) at ../glib/gmain.c:3454
#26 g_main_context_dispatch (context=0x7fffd4005010) at ../glib/gmain.c:4172
#27 0x00007fffe84a2118 in g_main_context_iterate.constprop.0 (context=0x7fffd4005010, block=1, dispatch=1, self=<optimized out>) at ../glib/gmain.c:4248
#28 0x00007fffe8448f00 in g_main_context_iteration (context=0x7fffd4005010, may_block=1) at ../glib/gmain.c:4313
#29 0x00007fffeeaee5fa in QEventDispatcherGlib::processEvents (this=0x5555555aac60, flags=...) at kernel/qeventdispatcher_glib.cpp:423
#30 0x00007fffeea9bf3a in QEventLoop::exec (this=this@entry=0x7fffffffd3a0, flags=..., flags@entry=...) at ../../include/QtCore/../../src/corelib/global/qflags.h:69
#31 0x00007fffeeaa4002 in QCoreApplication::exec () at ../../include/QtCore/../../src/corelib/global/qflags.h:121
#32 0x00007fffeef5fad0 in QGuiApplication::exec () at kernel/qguiapplication.cpp:1863
#33 0x00007fffef7aecd9 in QApplication::exec () at kernel/qapplication.cpp:2832
#34 0x0000555555558dbf in main (argc=<optimized out>, argv=<optimized out>) at /usr/src/debug/kmail-22.12.3-1.fc37.x86_64/src/main.cpp:185