Fake du email

[canetoad]

2. What is more likely

Is that someone with whom you share emails has picked up an email worm. The worm goes through the infected computer, read emails and address books and fires of garbage emails made up of text scraped randomly from the infected computer.

That's how it knows your email address. It's also possible that you have the worm active on your machine. Full virus/security scan should find it.