Some data points... To address those who might think an address book got hacked or a forum got slurped... Etc.
I have had a me.com account for over three years. Have never recieved any email to that account even for apple as a welcome ( was before they sent welcome emails. ). In short I don't use this account for sending emails, never have sent an email from it.
I noticed that ther were some emails waiting for me there. I was shocked to see it we spam, so I googled for this and found this any many other threads about this same spam email. I kind of figured apple got hacked and this definitely is one more I indicator my suspicions are correct. No way for anyone to hack my address book as it's not an email account listed, shared or used. Not to mention I'm aware of about a dozen others with this same spa message.
Apple..... we expect better than this. You lost positive control of a lot of email addresses.