The virus is using your address, plucked from someone elses system. The reason you get the bounce (a nice warning) is that someone else on the hit list is no longer using their address.

Look at the FULL HEADER (you can do this online, without downloading the message) or if it's on your system, view full header and see the real source.

Don't Open.

Sounds like Klez as usual.

When I get these from myself (I have more than a few email addresses) on a weekend when I was working out of town, I know it's from someone else.

Correct: You can NOT get these from reading web based mail or webtv accounts that never download anything to your computer.