Outlook crashed 2 times today when showing some encrypted mail with (partial) non-encrypted appendix was activated and the according message box pops up / is closed (not sure). Error log for 2nd crash appended, not sure if I captured the correct moment.
Also, this doesn't happen regularly. I tried a lot to actively cause the crash and didn't manage. But I did manage to make the colors from the "Vertrauen" (green) and "Verschlüsselt" (blue) bars disappear one time, don't know how.