Myself and, independently, a couple of my friends received emails off other friends telling us how to get a free £60 voucher from Sainsbury’s. All you have to do is send the email on to 10 of your friends, cc’ing an email address at customerservices dot com.
Checking the customerservices.com registration details, it’s someone in Indiana. There’s no link to Sainsbury’s. The customerservices dot com website is a junk portal page.
What I suspect is happening is that someone’s started off a viral email that is harvesting real email accounts via the CC in the email.
The general rule of thumb is that if something sounds too good to be true, it usually is!