It only sends that email when you either type in your email address or username and click "I have forgot my password". Maybe someone else did it for your username. Nevermind, they can't get to your password anyway because you are the only one it sends the email to, so your account is safe.
this worries me i just had an e mail tellin me my pasword, but i havent loggrd on until now !? a bit worried .......