KMail Crash after sending large file

Morning all,
my wife tried to send some 230 MB by mail (no comments please!), causing KMail to crash with a ‘dumpDeadLetters’ Error. I created https://bugs.kde.org/show_bug.cgi?id=352105 for this.
Problem remains that kmail immeadiately crashes after start. How can I get the mail in trouble out of the akonadi-DB (which still works by the way)? I’m not really a fan of deleting everything under the users home directory that looks like KMail…
Any help appreciated!
Thanks!

It’s probably not in the database (which is just a cache anyway).
Try to delete ~/.kde4/share/apps/kmail2/autosave/.

That helped, thanks!