Outlook freezes while I am working on other programs. And then I notice that Outlook is not downloading e-mails. The problem can only be solved by a shutdown of Windows. When doing so, Windows says that Outlook is still working, while the Task manager does not mention it as an active routine. After restarting Windows every thing works perfectely. So Outlook is not hanging while using it, but when open as a background routine. I do not send e-Mails out from pdf-Documents, so this cannot be the reason for the problem.