Outlook periodically (1-2 times per day)locks up when trying to send email. I digitally sign all mail. When Outlook became non-responsive, I closed the message window (would not allow me to save). When asked Yes/No/Cancel about saving the email, I could not save. When I clicked No, the message window closed and the prompt for my CAC pin appeared. When I entered my pin, Outlook crashed and restarted.