I don't have any idea, but you might want to try using Microsoft Live Mail, it's like a newer version of Outlook.
I use Mozilla Thunderbird myself but I have used Live Mail in the past, and it worked well.
Windows Vista and Windows 7 do NOT support Outlook Express which is designed for Windows XP.
Outlook Express isn't available in Windows Vista or Windows 7—you can't download it or run it on either version of Windows. However, you can install an e‑mail program from another company or use Windows Live Mail—a free program that is part of Windows Live Essentials. http://windows.microsoft.com/en-ca/windows-live/essentials-other#essentials=overviewother