Does anyone has received a email saying that you won the lottery?

I did received one of those emails and it says that I won 850.000.00 dollars in a lotto draw where they randomly selected a batch of 50,000 international emails and that my emails was selected and won that prize but the question is: are these real? or they just want my money? Because i been replying this person to "claim" my prize and that I have to pay a fee of US$1240 to open a non-resident account in south africa to make an international wire transfer to my bank account here in USA. At first, the guy was pretty convincing but then he said that i had to send the money somewhere in London...and that's weird! why would I send money to London to open a bank account in south africa? I would like to know if these guys just want my money and if you have experienced something similiar and tell me if this are real or they just fake? thanx!