The safest response is to use mailwasher - there's a free download. I check all my email on the server with it - the viruses and spam can be blocked or bounced before they get to your computer. You can see the content as well. After mailwasher checks and deletes the incoming stuff, only then do I check mail through the email program. This requires that email downloading not be done automatically but it's worth it. Mailwasher sets up a friends list and a blacklist. This is a reasonable defensive move.