I've received about 20 of these damn messages. Never opened any of them though. I use Outlook Express but I have the preview pane turned off. If I receive a suspicious email, I usually just look at the message source. You can look at a message's source with OE by right clicking on the email, choose 'properties', click on the 'details' tab and click on the 'message source' button. You get all the headers plus the message in a text format so no insidious html or javascript will be triggered. You can block future emails from these spammeisters by choosing from the menubar 'message->Block sender' but this doesn't seem to be that effective as spammers are constantly changing their email addresses.

Mydoom, which first appeared on Monday afternoon, infects computers using the Microsoft Corporation's Windows operating systems and is spread as an attachment to seemingly harmless e-mail messages that may carry innocuous subject lines like "Hello," and "Mail Transaction Failed." The body of the messages carry one of several plausible-sounding texts, often falling just outside the technical comprehension of the ordinary computer user, including, "The message contains Unicode characters and has been sent as a binary attachment."

Here's the Symantec page for this virus.