Is there any way to stop ‘adult’ spam emails?

Ruth is upset because she's receiving unwanted emails at Yahoo Mail and the firm isn't helping. Is there anything she can do?

For some time now, I have been receiving from five to 20 unwanted "adult" emails per day. I followed Yahoo's advice on how to block these emails, but I still am receiving them. I contacted Yahoo again, but within the blink of an eye, I received a standard response email stating that my case was closed. I have also emailed the CEO of Yahoo UK, and I am angry with the complete indifference that Yahoo has shown.

How can I stop these emails? I was thinking of sending them back to the sender, but I'm wondering if it will have any impact. Ruth