it is not a matter of whether they are punished or not. it is a matter of how many greedy people will fall into their traps. as you know it is not only uk lottery but lotteries from spain and italy. but all i know is that they all operate from nigeria. hence they are all under 419 nigerian scams. they are many anti-scam and fraud websites where you can complain but they won’t help much. such as fbi in the usa.
the more people will reply, either innocently or knowingly, the more brave these scammers are. remember, these scammers operate from a country where there are no law.
the best thing to do is to delete all these scams or put them in the junk folders.
treat these scams like some kind of disease that cannot be cure, but at least you can stay away from by taking precautions.

Actually you can report it but there is not a lot Yahoo can do about these scams. The messages come from computers which are taken over by hackers and used for this purpose. It is almost impossible to catch these people. The main thing is for us to be careful not to fall for their scams. Don’t answer just delete them Good luck and be careful.