Just knowing who sent you the mail might not be enough. Some of these email viruses will send copies of themselves to everyone in your address book. If some Flyertalk friend of yours is a victim, the virus might send of copy of itself to you, totally unbeknownst to your friend. This message comes from your friend’s computer with his email address as the sender. It’s entirely possible to get infected email from a friend who has no malicious intent. In fact, that’s why email viruses spread so quickly. They get sent (unknowingly) by trusted friends who are victims of the virus.