Outlook express is one of the email readers that most hackers are targeting. I would suggest that you use the free reader Thunderbird, and do a trial of Mailwasher. Mailwasher allows you to preview your email and delete anything that does not look right before you download it to your email reader. I've been using Microsoft Security Essentials, which is free, for about a year, and it will scan your email as it is downloaded (as well as check for all kinds of malware as you are browsing). Between these two programs, and Eset antivirus before MSE, I have been virus free for at least 7 or 8 years.